Many msh files (e.g. those in BFX) have multiple models assigned to the same index (MNDX). Indices should be linked only to the first model that uses them to ensure proper skinning.

addons/io_scene_swbf_msh/__init__.py

@@ -1,7 +1,7 @@
 bl_info = {
     'name': 'SWBF .msh Import-Export',
     'author': 'Will Snyder, SleepKiller',
-    "version": (1, 0, 0),
+    "version": (1, 2, 1),
     'blender': (2, 80, 0),
     'location': 'File > Import-Export',
     'description': 'Export as SWBF .msh file',

addons/io_scene_swbf_msh/msh_scene_read.py

@@ -203,7 +203,9 @@ def _read_modl(modl: Reader, materials_list: List[Material]) -> Model:
 
                 global model_counter
                 global mndx_remap
-                mndx_remap[index] = model_counter
+
+                if index not in mndx_remap:
+                    mndx_remap[index] = model_counter
 
                 model_counter += 1