I installed the blender source tool, tried to open .mdl file using crowbar. Failed. Got this message:

Python: Traceback (most recent call last):
File "C:\Users\monde\AppData\Roaming\Blender Foundation\Blender\3.5\scripts\addons\SourceIO-master\source1_operators.py", line 54, in execute
model_container = import_model(mdl_path.open('rb'), vvd_file.open('rb'), vtx_file.open('rb'), self.scale,
File "C:\Users\monde\AppData\Roaming\Blender Foundation\Blender\3.5\scripts\addons\SourceIO-master\source1\mdl\import_mdl.py", line 180, in import_model
mesh_data.polygons.foreach_set("use_smooth", np.ones(len(mesh_data.polygons)))
TypeError: couldn't access the py sequence

How to fix?