diff --git a/io_scene_psk_psa/helpers.py b/io_scene_psk_psa/helpers.py
index 4cdc737..54c1b2c 100644
--- a/io_scene_psk_psa/helpers.py
+++ b/io_scene_psk_psa/helpers.py
@@ -1,10 +1,10 @@
 import datetime
-from collections import Counter
 import re
+from collections import Counter
 from typing import List, Iterable
 
+import bpy.types
 from bpy.types import NlaStrip, Object
-from .types import BoneGroupListItem
 
 
 class Timer:
@@ -47,7 +47,7 @@ def get_nla_strips_in_timeframe(animation_data, frame_min, frame_max) -> List[Nl
     return strips
 
 
-def populate_bone_group_list(armature_object: Object, bone_group_list: Iterable[BoneGroupListItem]) -> None:
+def populate_bone_group_list(armature_object: Object, bone_group_list: bpy.types.Collection) -> None:
     """
     Updates the bone group collection.
 
diff --git a/io_scene_psk_psa/psa/builder.py b/io_scene_psk_psa/psa/builder.py
index 969b8c6..f57361d 100644
--- a/io_scene_psk_psa/psa/builder.py
+++ b/io_scene_psk_psa/psa/builder.py
@@ -1,4 +1,4 @@
-from typing import Dict, Iterable
+from typing import Dict
 
 from bpy.types import Action
 
@@ -217,7 +217,8 @@ def build_psa(context, options: PsaBuildOptions) -> Psa:
 
     # Add prefixes and suffices to the names of the export sequences and strip whitespace.
     for export_sequence in export_sequences:
-        export_sequence.name = f'{options.sequence_name_prefix}{export_sequence.name}{options.sequence_name_suffix}'.strip()
+        export_sequence.name = f'{options.sequence_name_prefix}{export_sequence.name}{options.sequence_name_suffix}'
+        export_sequence.name = export_sequence.name.strip()
 
     # Now build the PSA sequences.
     # We actually alter the timeline frame and simply record the resultant pose bone matrices.
diff --git a/io_scene_psk_psa/psa/exporter.py b/io_scene_psk_psa/psa/exporter.py
index 90e93ba..59bd82d 100644
--- a/io_scene_psk_psa/psa/exporter.py
+++ b/io_scene_psk_psa/psa/exporter.py
@@ -1,7 +1,5 @@
 import fnmatch
-import re
 import sys
-from collections import Counter
 from typing import Type
 
 import bpy
@@ -16,17 +14,19 @@ from ..helpers import *
 from ..types import BoneGroupListItem
 
 
+def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
+    section = Section()
+    section.name = name
+    if data_type is not None and data is not None:
+        section.data_size = sizeof(data_type)
+        section.data_count = len(data)
+    fp.write(section)
+    if data is not None:
+        for datum in data:
+            fp.write(datum)
+
+
 def export_psa(psa: Psa, path: str):
-    def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
-        section = Section()
-        section.name = name
-        if data_type is not None and data is not None:
-            section.data_size = sizeof(data_type)
-            section.data_count = len(data)
-        fp.write(section)
-        if data is not None:
-            for datum in data:
-                fp.write(datum)
     with open(path, 'wb') as fp:
         write_section(fp, b'ANIMHEAD')
         write_section(fp, b'BONENAMES', Psa.Bone, psa.bones)
@@ -61,16 +61,19 @@ def psa_export_property_group_animation_data_override_poll(_context, obj):
     return obj.animation_data is not None
 
 
+empty_set = set()
+
+
 class PsaExportPropertyGroup(PropertyGroup):
     root_motion: BoolProperty(
         name='Root Motion',
-        options=set(),
+        options=empty_set,
         default=False,
         description='The root bone will be transformed as it appears in the scene',
     )
     should_override_animation_data: BoolProperty(
         name='Override Animation Data',
-        options=set(),
+        options=empty_set,
         default=False,
         description='Use the animation data from a different object instead of the selected object'
     )
@@ -80,7 +83,7 @@ class PsaExportPropertyGroup(PropertyGroup):
     )
     sequence_source: EnumProperty(
         name='Source',
-        options=set(),
+        options=empty_set,
         description='',
         items=(
             ('ACTIONS', 'Actions', 'Sequences will be exported using actions', 'ACTION', 0),
@@ -90,7 +93,7 @@ class PsaExportPropertyGroup(PropertyGroup):
     )
     fps_source: EnumProperty(
         name='FPS Source',
-        options=set(),
+        options=empty_set,
         description='',
         items=(
             ('SCENE', 'Scene', '', 'SCENE_DATA', 0),
@@ -100,7 +103,7 @@ class PsaExportPropertyGroup(PropertyGroup):
             ('CUSTOM', 'Custom', '', 2)
         )
     )
-    fps_custom: FloatProperty(default=30.0, min=sys.float_info.epsilon, soft_min=1.0, options=set(), step=100,
+    fps_custom: FloatProperty(default=30.0, min=sys.float_info.epsilon, soft_min=1.0, options=empty_set, step=100,
                               soft_max=60.0)
     action_list: CollectionProperty(type=PsaExportActionListItem)
     action_list_index: IntProperty(default=0)
@@ -108,7 +111,7 @@ class PsaExportPropertyGroup(PropertyGroup):
     marker_list_index: IntProperty(default=0)
     bone_filter_mode: EnumProperty(
         name='Bone Filter',
-        options=set(),
+        options=empty_set,
         description='',
         items=(
             ('ALL', 'All', 'All bones will be exported.'),
@@ -121,7 +124,7 @@ class PsaExportPropertyGroup(PropertyGroup):
     should_use_original_sequence_names: BoolProperty(
         default=False,
         name='Original Names',
-        options=set(),
+        options=empty_set,
         update=should_use_original_sequence_names_updated,
         description='If the action was imported from the PSA Import panel, the original name of the sequence will be '
                     'used instead of the Blender action name',
@@ -129,12 +132,12 @@ class PsaExportPropertyGroup(PropertyGroup):
     should_trim_timeline_marker_sequences: BoolProperty(
         default=True,
         name='Trim Sequences',
-        options=set(),
+        options=empty_set,
         description='Frames without NLA track information at the boundaries of timeline markers will be excluded from '
                     'the exported sequences '
     )
-    sequence_name_prefix: StringProperty(name='Prefix', options=set())
-    sequence_name_suffix: StringProperty(name='Suffix', options=set())
+    sequence_name_prefix: StringProperty(name='Prefix', options=empty_set)
+    sequence_name_suffix: StringProperty(name='Suffix', options=empty_set)
     sequence_filter_name: StringProperty(
         default='',
         name='Filter by Name',
@@ -143,14 +146,14 @@ class PsaExportPropertyGroup(PropertyGroup):
     sequence_use_filter_invert: BoolProperty(
         default=False,
         name='Invert',
-        options=set(),
+        options=empty_set,
         description='Invert filtering (show hidden items, and vice versa)')
     sequence_filter_asset: BoolProperty(
         default=False,
         name='Show assets',
-        options=set(),
+        options=empty_set,
         description='Show actions that belong to an asset library')
-    sequence_use_filter_sort_reverse: BoolProperty(default=True, options=set())
+    sequence_use_filter_sort_reverse: BoolProperty(default=True, options=empty_set)
 
 
 def is_bone_filter_mode_item_available(context, identifier):
@@ -182,13 +185,13 @@ class PsaExportOperator(Operator, ExportHelper):
         try:
             cls._check_context(context)
         except RuntimeError as e:
-            cls.poll_message_set((str(e)))
+            cls.poll_message_set(str(e))
             return False
         return True
 
     def draw(self, context):
         layout = self.layout
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
 
         # FPS
         layout.prop(pg, 'fps_source', text='FPS')
@@ -291,7 +294,7 @@ class PsaExportOperator(Operator, ExportHelper):
         except RuntimeError as e:
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
 
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         self.armature = context.view_layer.objects.active
 
         # Populate actions list.
@@ -326,7 +329,7 @@ class PsaExportOperator(Operator, ExportHelper):
         return {'RUNNING_MODAL'}
 
     def execute(self, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
 
         actions = [x.action for x in pg.action_list if x.is_selected]
         marker_names = [x.name for x in pg.marker_list if x.is_selected]
@@ -349,6 +352,7 @@ class PsaExportOperator(Operator, ExportHelper):
 
         try:
             psa = build_psa(context, options)
+            self.report({'INFO'}, f'PSA export successful')
         except RuntimeError as e:
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
@@ -358,7 +362,7 @@ class PsaExportOperator(Operator, ExportHelper):
         return {'FINISHED'}
 
 
-def filter_sequences(pg: PsaExportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[int]:
+def filter_sequences(pg: PsaExportPropertyGroup, sequences) -> List[int]:
     bitflag_filter_item = 1 << 30
     flt_flags = [bitflag_filter_item] * len(sequences)
 
@@ -381,7 +385,7 @@ def filter_sequences(pg: PsaExportPropertyGroup, sequences: bpy.types.bpy_prop_c
     return flt_flags
 
 
-def get_visible_sequences(pg: PsaExportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[PsaExportActionListItem]:
+def get_visible_sequences(pg: PsaExportPropertyGroup, sequences) -> List[PsaExportActionListItem]:
     visible_sequences = []
     for i, flag in enumerate(filter_sequences(pg, sequences)):
         if bool(flag & (1 << 30)):
@@ -402,7 +406,7 @@ class PSA_UL_ExportSequenceList(UIList):
             layout.label(text='', icon='ASSET_MANAGER')
 
     def draw_filter(self, context, layout):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         row = layout.row()
         subrow = row.row(align=True)
         subrow.prop(pg, 'sequence_filter_name', text="")
@@ -414,7 +418,7 @@ class PSA_UL_ExportSequenceList(UIList):
             subrow.prop(pg, 'sequence_filter_asset', icon_only=True, icon='ASSET_MANAGER')
 
     def filter_items(self, context, data, prop):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         actions = getattr(data, prop)
         flt_flags = filter_sequences(pg, actions)
         flt_neworder = bpy.types.UI_UL_list.sort_items_by_name(actions, 'name')
@@ -438,14 +442,14 @@ class PsaExportActionsSelectAll(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         item_list = cls.get_item_list(context)
         visible_sequences = get_visible_sequences(pg, item_list)
         has_unselected_sequences = any(map(lambda item: not item.is_selected, visible_sequences))
         return has_unselected_sequences
 
     def execute(self, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         sequences = self.get_item_list(context)
         for sequence in get_visible_sequences(pg, sequences):
             sequence.is_selected = True
@@ -474,7 +478,7 @@ class PsaExportActionsDeselectAll(Operator):
         return len(item_list) > 0 and has_selected_items
 
     def execute(self, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         item_list = self.get_item_list(context)
         for sequence in get_visible_sequences(pg, item_list):
             sequence.is_selected = False
@@ -489,13 +493,13 @@ class PsaExportBoneGroupsSelectAll(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         item_list = pg.bone_group_list
         has_unselected_items = any(map(lambda action: not action.is_selected, item_list))
         return len(item_list) > 0 and has_unselected_items
 
     def execute(self, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         for item in pg.bone_group_list:
             item.is_selected = True
         return {'FINISHED'}
@@ -509,13 +513,13 @@ class PsaExportBoneGroupsDeselectAll(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         item_list = pg.bone_group_list
         has_selected_actions = any(map(lambda action: action.is_selected, item_list))
         return len(item_list) > 0 and has_selected_actions
 
     def execute(self, context):
-        pg = context.scene.psa_export
+        pg = getattr(context.scene, 'psa_export')
         for action in pg.bone_group_list:
             action.is_selected = False
         return {'FINISHED'}
diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index 0b60958..7150230 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -26,38 +26,40 @@ class PsaImportOptions(object):
         self.action_name_prefix = ''
 
 
+class ImportBone(object):
+    def __init__(self, psa_bone: Psa.Bone):
+        self.psa_bone: Psa.Bone = psa_bone
+        self.parent: Optional[ImportBone] = None
+        self.armature_bone = None
+        self.pose_bone = None
+        self.orig_loc: Vector = Vector()
+        self.orig_quat: Quaternion = Quaternion()
+        self.post_quat: Quaternion = Quaternion()
+        self.fcurves = []
+
+
+def calculate_fcurve_data(import_bone: ImportBone, key_data: []):
+    # Convert world-space transforms to local-space transforms.
+    key_rotation = Quaternion(key_data[0:4])
+    key_location = Vector(key_data[4:])
+    q = import_bone.post_quat.copy()
+    q.rotate(import_bone.orig_quat)
+    quat = q
+    q = import_bone.post_quat.copy()
+    if import_bone.parent is None:
+        q.rotate(key_rotation.conjugated())
+    else:
+        q.rotate(key_rotation)
+    quat.rotate(q.conjugated())
+    loc = key_location - import_bone.orig_loc
+    loc.rotate(import_bone.post_quat.conjugated())
+    return quat.w, quat.x, quat.y, quat.z, loc.x, loc.y, loc.z
+
+
 def import_psa(psa_reader: PsaReader, armature_object, options: PsaImportOptions):
     sequences = map(lambda x: psa_reader.sequences[x], options.sequence_names)
     armature_data = armature_object.data
 
-    class ImportBone(object):
-        def __init__(self, psa_bone: Psa.Bone):
-            self.psa_bone: Psa.Bone = psa_bone
-            self.parent: Optional[ImportBone] = None
-            self.armature_bone = None
-            self.pose_bone = None
-            self.orig_loc: Vector = Vector()
-            self.orig_quat: Quaternion = Quaternion()
-            self.post_quat: Quaternion = Quaternion()
-            self.fcurves = []
-
-    def calculate_fcurve_data(import_bone: ImportBone, key_data: []):
-        # Convert world-space transforms to local-space transforms.
-        key_rotation = Quaternion(key_data[0:4])
-        key_location = Vector(key_data[4:])
-        q = import_bone.post_quat.copy()
-        q.rotate(import_bone.orig_quat)
-        quat = q
-        q = import_bone.post_quat.copy()
-        if import_bone.parent is None:
-            q.rotate(key_rotation.conjugated())
-        else:
-            q.rotate(key_rotation)
-        quat.rotate(q.conjugated())
-        loc = key_location - import_bone.orig_loc
-        loc.rotate(import_bone.post_quat.conjugated())
-        return quat.w, quat.x, quat.y, quat.z, loc.x, loc.y, loc.z
-
     # Create an index mapping from bones in the PSA to bones in the target armature.
     psa_to_armature_bone_indices = {}
     armature_bone_names = [x.name for x in armature_data.bones]
@@ -176,7 +178,8 @@ def import_psa(psa_reader: PsaReader, armature_object, options: PsaImportOptions
                         fcurve_frame_data = sequence_data_matrix[:, bone_index, fcurve_index]
                         last_written_datum = 0
                         for frame_index, datum in enumerate(fcurve_frame_data):
-                            # If the f-curve data is not different enough to the last written frame, un-mark this data for writing.
+                            # If the f-curve data is not different enough to the last written frame,
+                            # un-mark this data for writing.
                             if frame_index > 0 and abs(datum - last_written_datum) < threshold:
                                 keyframe_write_matrix[frame_index, bone_index, fcurve_index] = 0
                             else:
@@ -217,9 +220,12 @@ def import_psa(psa_reader: PsaReader, armature_object, options: PsaImportOptions
             nla_track.strips.new(name=action.name, start=0, action=action)
 
 
+empty_set = set()
+
+
 class PsaImportActionListItem(PropertyGroup):
-    action_name: StringProperty(options=set())
-    is_selected: BoolProperty(default=False, options=set())
+    action_name: StringProperty(options=empty_set)
+    is_selected: BoolProperty(default=False, options=empty_set)
 
 
 def load_psa_file(context):
@@ -246,7 +252,7 @@ def on_psa_file_path_updated(property, context):
 
 
 class PsaBonePropertyGroup(PropertyGroup):
-    bone_name: StringProperty(options=set())
+    bone_name: StringProperty(options=empty_set)
 
 
 class PsaDataPropertyGroup(PropertyGroup):
@@ -255,37 +261,37 @@ class PsaDataPropertyGroup(PropertyGroup):
 
 
 class PsaImportPropertyGroup(PropertyGroup):
-    psa_file_path: StringProperty(default='', options=set(), update=on_psa_file_path_updated, name='PSA File Path')
+    psa_file_path: StringProperty(default='', options=empty_set, update=on_psa_file_path_updated, name='PSA File Path')
     psa_error: StringProperty(default='')
     psa: PointerProperty(type=PsaDataPropertyGroup)
     sequence_list: CollectionProperty(type=PsaImportActionListItem)
     sequence_list_index: IntProperty(name='', default=0)
     should_clean_keys: BoolProperty(default=True, name='Clean Keyframes',
                                     description='Exclude unnecessary keyframes from being written to the actions',
-                                    options=set())
+                                    options=empty_set)
     should_use_fake_user: BoolProperty(default=True, name='Fake User',
                                        description='Assign each imported action a fake user so that the data block is saved even it has no users',
-                                       options=set())
+                                       options=empty_set)
     should_stash: BoolProperty(default=False, name='Stash',
                                description='Stash each imported action as a strip on a new non-contributing NLA track',
-                               options=set())
-    should_use_action_name_prefix: BoolProperty(default=False, name='Prefix Action Name', options=set())
-    action_name_prefix: StringProperty(default='', name='Prefix', options=set())
-    should_overwrite: BoolProperty(default=False, name='Reuse Existing Actions', options=set(),
+                               options=empty_set)
+    should_use_action_name_prefix: BoolProperty(default=False, name='Prefix Action Name', options=empty_set)
+    action_name_prefix: StringProperty(default='', name='Prefix', options=empty_set)
+    should_overwrite: BoolProperty(default=False, name='Reuse Existing Actions', options=empty_set,
                                    description='If an action with a matching name already exists, the existing action will have it\'s data overwritten instead of a new action being created')
-    should_write_keyframes: BoolProperty(default=True, name='Keyframes', options=set())
-    should_write_metadata: BoolProperty(default=True, name='Metadata', options=set(),
+    should_write_keyframes: BoolProperty(default=True, name='Keyframes', options=empty_set)
+    should_write_metadata: BoolProperty(default=True, name='Metadata', options=empty_set,
                                         description='Additional data will be written to the custom properties of the Action (e.g., frame rate)')
     sequence_filter_name: StringProperty(default='', options={'TEXTEDIT_UPDATE'})
-    sequence_filter_is_selected: BoolProperty(default=False, options=set(), name='Only Show Selected',
+    sequence_filter_is_selected: BoolProperty(default=False, options=empty_set, name='Only Show Selected',
                                               description='Only show selected sequences')
-    sequence_use_filter_invert: BoolProperty(default=False, options=set())
+    sequence_use_filter_invert: BoolProperty(default=False, options=empty_set)
     sequence_use_filter_regex: BoolProperty(default=False, name='Regular Expression',
-                                            description='Filter using regular expressions', options=set())
+                                            description='Filter using regular expressions', options=empty_set)
     select_text: PointerProperty(type=bpy.types.Text)
 
 
-def filter_sequences(pg: PsaImportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[int]:
+def filter_sequences(pg: PsaImportPropertyGroup, sequences) -> List[int]:
     bitflag_filter_item = 1 << 30
     flt_flags = [bitflag_filter_item] * len(sequences)
 
@@ -319,8 +325,7 @@ def filter_sequences(pg: PsaImportPropertyGroup, sequences: bpy.types.bpy_prop_c
     return flt_flags
 
 
-def get_visible_sequences(pg: PsaImportPropertyGroup, sequences: bpy.types.bpy_prop_collection) -> List[
-    PsaImportActionListItem]:
+def get_visible_sequences(pg: PsaImportPropertyGroup, sequences) -> List[PsaImportActionListItem]:
     bitflag_filter_item = 1 << 30
     visible_sequences = []
     for i, flag in enumerate(filter_sequences(pg, sequences)):
@@ -330,26 +335,25 @@ def get_visible_sequences(pg: PsaImportPropertyGroup, sequences: bpy.types.bpy_p
 
 
 class PSA_UL_SequenceList(UIList):
-
-    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+    def draw_item(self, context, layout, data, item, icon, active_data, active_property, index, flt_flag):
         row = layout.row(align=True)
         split = row.split(align=True, factor=0.75)
         column = split.row(align=True)
         column.alignment = 'LEFT'
         column.prop(item, 'is_selected', icon_only=True)
-        column.label(text=item.action_name)
+        column.label(text=getattr(item, 'action_name'))
 
     def draw_filter(self, context, layout):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         row = layout.row()
-        subrow = row.row(align=True)
-        subrow.prop(pg, 'sequence_filter_name', text="")
-        subrow.prop(pg, 'sequence_use_filter_invert', text="", icon='ARROW_LEFTRIGHT')
-        subrow.prop(pg, 'sequence_use_filter_regex', text="", icon='SORTBYEXT')
-        subrow.prop(pg, 'sequence_filter_is_selected', text="", icon='CHECKBOX_HLT')
+        sub_row = row.row(align=True)
+        sub_row.prop(pg, 'sequence_filter_name', text="")
+        sub_row.prop(pg, 'sequence_use_filter_invert', text="", icon='ARROW_LEFTRIGHT')
+        sub_row.prop(pg, 'sequence_use_filter_regex', text="", icon='SORTBYEXT')
+        sub_row.prop(pg, 'sequence_filter_is_selected', text="", icon='CHECKBOX_HLT')
 
     def filter_items(self, context, data, property):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         sequences = getattr(data, property)
         flt_flags = filter_sequences(pg, sequences)
         flt_neworder = bpy.types.UI_UL_list.sort_items_by_name(sequences, 'action_name')
@@ -372,7 +376,7 @@ class PsaImportSequencesFromText(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         return len(pg.sequence_list) > 0
 
     def invoke(self, context, event):
@@ -380,12 +384,12 @@ class PsaImportSequencesFromText(Operator):
 
     def draw(self, context):
         layout = self.layout
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         layout.label(icon='INFO', text='Each sequence name should be on a new line.')
         layout.prop(pg, 'select_text', text='')
 
     def execute(self, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         if pg.select_text is None:
             self.report({'ERROR_INVALID_CONTEXT'}, 'No text block selected')
             return {'CANCELLED'}
@@ -408,13 +412,13 @@ class PsaImportSequencesSelectAll(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         visible_sequences = get_visible_sequences(pg, pg.sequence_list)
         has_unselected_actions = any(map(lambda action: not action.is_selected, visible_sequences))
         return len(visible_sequences) > 0 and has_unselected_actions
 
     def execute(self, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         visible_sequences = get_visible_sequences(pg, pg.sequence_list)
         for sequence in visible_sequences:
             sequence.is_selected = True
@@ -429,13 +433,13 @@ class PsaImportSequencesDeselectAll(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         visible_sequences = get_visible_sequences(pg, pg.sequence_list)
         has_selected_sequences = any(map(lambda sequence: sequence.is_selected, visible_sequences))
         return len(visible_sequences) > 0 and has_selected_sequences
 
     def execute(self, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         visible_sequences = get_visible_sequences(pg, pg.sequence_list)
         for sequence in visible_sequences:
             sequence.is_selected = False
@@ -451,7 +455,7 @@ class PSA_PT_ImportPanel_Advanced(Panel):
 
     def draw(self, context):
         layout = self.layout
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
 
         col = layout.column(heading="Options")
         col.use_property_split = True
@@ -476,11 +480,11 @@ class PSA_PT_ImportPanel(Panel):
 
     @classmethod
     def poll(cls, context):
-        return context.object.type == 'ARMATURE'
+        return context.view_layer.objects.active.type == 'ARMATURE'
 
     def draw(self, context):
         layout = self.layout
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
 
         row = layout.row(align=True)
         row.operator(PsaImportSelectFile.bl_idname, text='', icon='FILEBROWSER')
@@ -552,7 +556,7 @@ class PsaImportSelectFile(Operator):
     filter_glob: bpy.props.StringProperty(default="*.psa", options={'HIDDEN'})
 
     def execute(self, context):
-        context.scene.psa_import.psa_file_path = self.filepath
+        getattr(context.scene, 'psa_import').psa_file_path = self.filepath
         return {"FINISHED"}
 
     def invoke(self, context, event):
@@ -568,14 +572,14 @@ class PsaImportOperator(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         active_object = context.view_layer.objects.active
         if active_object is None or active_object.type != 'ARMATURE':
             return False
         return any(map(lambda x: x.is_selected, pg.sequence_list))
 
     def execute(self, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         psa_reader = PsaReader(pg.psa_file_path)
         sequence_names = [x.action_name for x in pg.sequence_list if x.is_selected]
 
@@ -613,7 +617,7 @@ class PsaImportFileSelectOperator(Operator, ImportHelper):
         return {'RUNNING_MODAL'}
 
     def execute(self, context):
-        pg = context.scene.psa_import
+        pg = getattr(context.scene, 'psa_import')
         pg.psa_file_path = self.filepath
         return {'FINISHED'}
 
diff --git a/io_scene_psk_psa/psa/reader.py b/io_scene_psk_psa/psa/reader.py
index 25cf342..0f0fba8 100644
--- a/io_scene_psk_psa/psa/reader.py
+++ b/io_scene_psk_psa/psa/reader.py
@@ -8,8 +8,8 @@ from .data import *
 class PsaReader(object):
     """
     This class reads the sequences and bone information immediately upon instantiation and holds onto a file handle.
-    The keyframe data is not read into memory upon instantiation due to it's potentially very large size.
-    To read the key data for a particular sequence, call `read_sequence_keys`.
+    The keyframe data is not read into memory upon instantiation due to its potentially very large size.
+    To read the key data for a particular sequence, call :read_sequence_keys.
     """
 
     def __init__(self, path):
@@ -38,7 +38,8 @@ class PsaReader(object):
         return matrix
 
     def read_sequence_keys(self, sequence_name: str) -> List[Psa.Key]:
-        """ Reads and returns the key data for a sequence.
+        """
+        Reads and returns the key data for a sequence.
 
         :param sequence_name: The name of the sequence.
         :return: A list of Psa.Keys.
@@ -60,7 +61,7 @@ class PsaReader(object):
         return keys
 
     @staticmethod
-    def _read_types(fp, data_class: ctypes.Structure, section: Section, data):
+    def _read_types(fp, data_class, section: Section, data):
         buffer_length = section.data_size * section.data_count
         buffer = fp.read(buffer_length)
         offset = 0
@@ -86,7 +87,7 @@ class PsaReader(object):
                 # Skip keys on this pass. We will keep this file open and read from it as needed.
                 self.keys_data_offset = fp.tell()
                 fp.seek(section.data_size * section.data_count, 1)
-            elif section.name in [b'SCALEKEYS']:
+            elif section.name == b'SCALEKEYS':
                 fp.seek(section.data_size * section.data_count, 1)
             else:
                 raise RuntimeError(f'Unrecognized section "{section.name}"')
diff --git a/io_scene_psk_psa/psk/exporter.py b/io_scene_psk_psa/psk/exporter.py
index f5c1528..91c2566 100644
--- a/io_scene_psk_psa/psk/exporter.py
+++ b/io_scene_psk_psa/psk/exporter.py
@@ -1,7 +1,7 @@
 from typing import Type
 
-from bpy.props import BoolProperty, StringProperty, CollectionProperty, IntProperty, EnumProperty, PointerProperty
-from bpy.types import Operator, PropertyGroup, UIList, Material
+from bpy.props import BoolProperty, StringProperty, CollectionProperty, IntProperty, EnumProperty
+from bpy.types import Operator, PropertyGroup, UIList
 from bpy_extras.io_utils import ExportHelper
 
 from .builder import build_psk, PskBuildOptions, get_psk_input_objects
@@ -70,7 +70,7 @@ def is_bone_filter_mode_item_available(context, identifier):
 class PSK_UL_MaterialList(UIList):
     def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
         row = layout.row()
-        row.label(text=str(item.material_name), icon='MATERIAL')
+        row.label(text=str(getattr(item, 'material_name')), icon='MATERIAL')
 
 
 class MaterialListItem(PropertyGroup):
@@ -108,11 +108,11 @@ class PskMaterialListItemMoveUp(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psk_export
+        pg = getattr(context.scene, 'psk_export')
         return pg.material_list_index > 0
 
     def execute(self, context):
-        pg = context.scene.psk_export
+        pg = getattr(context.scene, 'psk_export')
         pg.material_list.move(pg.material_list_index, pg.material_list_index - 1)
         pg.material_list_index -= 1
         return {"FINISHED"}
@@ -126,11 +126,11 @@ class PskMaterialListItemMoveDown(Operator):
 
     @classmethod
     def poll(cls, context):
-        pg = context.scene.psk_export
+        pg = getattr(context.scene, 'psk_export')
         return pg.material_list_index < len(pg.material_list) - 1
 
     def execute(self, context):
-        pg = context.scene.psk_export
+        pg = getattr(context.scene, 'psk_export')
         pg.material_list.move(pg.material_list_index, pg.material_list_index + 1)
         pg.material_list_index += 1
         return {"FINISHED"}
@@ -157,7 +157,7 @@ class PskExportOperator(Operator, ExportHelper):
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
 
-        pg = context.scene.psk_export
+        pg = getattr(context.scene, 'psk_export')
 
         # Populate bone groups list.
         populate_bone_group_list(input_objects.armature_object, pg.bone_group_list)
@@ -178,8 +178,7 @@ class PskExportOperator(Operator, ExportHelper):
 
     def draw(self, context):
         layout = self.layout
-        scene = context.scene
-        pg = scene.psk_export
+        pg = getattr(context.scene, 'psk_export')
 
         layout.prop(pg, 'use_raw_mesh_data')
 
@@ -220,6 +219,7 @@ class PskExportOperator(Operator, ExportHelper):
         try:
             psk = build_psk(context, options)
             export_psk(psk, self.filepath)
+            self.report({'INFO'}, f'PSK export successful')
         except RuntimeError as e:
             self.report({'ERROR_INVALID_CONTEXT'}, str(e))
             return {'CANCELLED'}
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index 76f265a..7c1b50e 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -1,13 +1,13 @@
 import os
 import sys
 from math import inf
-from typing import Optional
+from typing import Optional, List
 
 import bmesh
 import bpy
 import numpy as np
 from bpy.props import BoolProperty, EnumProperty, FloatProperty, StringProperty
-from bpy.types import Operator, PropertyGroup
+from bpy.types import Operator, PropertyGroup, VertexGroup
 from bpy_extras.io_utils import ImportHelper
 from mathutils import Quaternion, Vector, Matrix
 
@@ -28,6 +28,24 @@ class PskImportOptions(object):
         self.bone_length = 1.0
 
 
+class ImportBone(object):
+    """
+    Intermediate bone type for the purpose of construction.
+    """
+    def __init__(self, index: int, psk_bone: Psk.Bone):
+        self.index: int = index
+        self.psk_bone: Psk.Bone = psk_bone
+        self.parent: Optional[ImportBone] = None
+        self.local_rotation: Quaternion = Quaternion()
+        self.local_translation: Vector = Vector()
+        self.world_rotation_matrix: Matrix = Matrix()
+        self.world_matrix: Matrix = Matrix()
+        self.vertex_group = None
+        self.orig_quat: Quaternion = Quaternion()
+        self.orig_loc: Vector = Vector()
+        self.post_quat: Quaternion = Quaternion()
+
+
 def import_psk(psk: Psk, context, options: PskImportOptions):
     armature_object = None
 
@@ -49,21 +67,6 @@ def import_psk(psk: Psk, context, options: PskImportOptions):
 
         bpy.ops.object.mode_set(mode='EDIT')
 
-        # Intermediate bone type for the purpose of construction.
-        class ImportBone(object):
-            def __init__(self, index: int, psk_bone: Psk.Bone):
-                self.index: int = index
-                self.psk_bone: Psk.Bone = psk_bone
-                self.parent: Optional[ImportBone] = None
-                self.local_rotation: Quaternion = Quaternion()
-                self.local_translation: Vector = Vector()
-                self.world_rotation_matrix: Matrix = Matrix()
-                self.world_matrix: Matrix = Matrix()
-                self.vertex_group = None
-                self.orig_quat: Quaternion = Quaternion()
-                self.orig_loc: Vector = Vector()
-                self.post_quat: Quaternion = Quaternion()
-
         import_bones = []
 
         for bone_index, psk_bone in enumerate(psk.bones):
@@ -213,7 +216,7 @@ def import_psk(psk: Psk, context, options: PskImportOptions):
 
         # Get a list of all bones that have weights associated with them.
         vertex_group_bone_indices = set(map(lambda weight: weight.bone_index, psk.weights))
-        vertex_groups = [None] * len(psk.bones)
+        vertex_groups: List[Optional[VertexGroup]] = [None] * len(psk.bones)
         for bone_index, psk_bone in map(lambda x: (x, psk.bones[x]), vertex_group_bone_indices):
             vertex_groups[bone_index] = mesh_object.vertex_groups.new(name=psk_bone.name.decode('windows-1252'))
 
@@ -234,16 +237,19 @@ def import_psk(psk: Psk, context, options: PskImportOptions):
         pass
 
 
+empty_set = set()
+
+
 class PskImportPropertyGroup(PropertyGroup):
     should_import_vertex_colors: BoolProperty(
         default=True,
-        options=set(),
+        options=empty_set,
         name='Vertex Colors',
         description='Import vertex colors from PSKX files, if available'
     )
     vertex_color_space: EnumProperty(
         name='Vertex Color Space',
-        options=set(),
+        options=empty_set,
         description='The source vertex color space',
         default='SRGBA',
         items=(
@@ -254,25 +260,25 @@ class PskImportPropertyGroup(PropertyGroup):
     should_import_vertex_normals: BoolProperty(
         default=True,
         name='Vertex Normals',
-        options=set(),
+        options=empty_set,
         description='Import vertex normals from PSKX files, if available'
     )
     should_import_extra_uvs: BoolProperty(
         default=True,
         name='Extra UVs',
-        options=set(),
+        options=empty_set,
         description='Import extra UV maps from PSKX files, if available'
     )
     should_import_mesh: BoolProperty(
         default=True,
         name='Import Mesh',
-        options=set(),
+        options=empty_set,
         description='Import mesh'
     )
     should_import_skeleton: BoolProperty(
         default=True,
         name='Import Skeleton',
-        options=set(),
+        options=empty_set,
         description='Import skeleton'
     )
     bone_length: FloatProperty(
@@ -281,7 +287,7 @@ class PskImportPropertyGroup(PropertyGroup):
         step=100,
         soft_min=1.0,
         name='Bone Length',
-        options=set(),
+        options=empty_set,
         description='Length of the bones'
     )
 
@@ -300,7 +306,7 @@ class PskImportOperator(Operator, ImportHelper):
         default='')
 
     def execute(self, context):
-        pg = context.scene.psk_import
+        pg = getattr(context.scene, 'psk_import')
 
         psk = read_psk(self.filepath)
 
@@ -319,7 +325,7 @@ class PskImportOperator(Operator, ImportHelper):
         return {'FINISHED'}
 
     def draw(self, context):
-        pg = context.scene.psk_import
+        pg = getattr(context.scene, 'psk_import')
         layout = self.layout
         layout.prop(pg, 'should_import_mesh')
         row = layout.column()
diff --git a/io_scene_psk_psa/psk/reader.py b/io_scene_psk_psa/psk/reader.py
index c68a1af..414a5f4 100644
--- a/io_scene_psk_psa/psk/reader.py
+++ b/io_scene_psk_psa/psk/reader.py
@@ -3,7 +3,7 @@ import ctypes
 from .data import *
 
 
-def _read_types(fp, data_class: ctypes.Structure, section: Section, data):
+def _read_types(fp, data_class, section: Section, data):
     buffer_length = section.data_size * section.data_count
     buffer = fp.read(buffer_length)
     offset = 0
diff --git a/io_scene_psk_psa/types.py b/io_scene_psk_psa/types.py
index 08cde91..1ffde62 100644
--- a/io_scene_psk_psa/types.py
+++ b/io_scene_psk_psa/types.py
@@ -1,12 +1,14 @@
 from bpy.props import StringProperty, IntProperty, BoolProperty
-from bpy.types import PropertyGroup, UIList
+from bpy.types import PropertyGroup, UIList, UILayout, Context, AnyType
 
 
 class PSX_UL_BoneGroupList(UIList):
-    def draw_item(self, context, layout, data, item, icon, active_data, active_propname, index):
+
+    def draw_item(self, context: Context, layout: UILayout, data: AnyType, item: AnyType, icon: int,
+                  active_data: AnyType, active_property: str, index: int = 0, flt_flag: int = 0):
         row = layout.row()
-        row.prop(item, 'is_selected', text=item.name)
-        row.label(text=str(item.count), icon='BONE_DATA')
+        row.prop(item, 'is_selected', text=getattr(item, 'name'))
+        row.label(text=str(getattr(item, 'count')), icon='BONE_DATA')
 
 
 class BoneGroupListItem(PropertyGroup):