Interesting that terminal now prints this kinda of errors!

RNA_def_struct_ui_text: 'MESH_OT_copy_face_settings' '' description ends with a '.' !

space_view3d_copy_attributes.py

@@ -668,7 +668,7 @@ for name, draw_func, poll_func in _layer_menu_data:
 
 
 class MESH_OT_CopyFaceSettings(bpy.types.Operator):
-    """Copy settings from active face to all selected faces."""
+    """Copy settings from active face to all selected faces"""
     bl_idname = 'mesh.copy_face_settings'
     bl_label = "Copy Face Settings"
     bl_options = {'REGISTER', 'UNDO'}