Material Baking error

Hi.
I’m not a blender user. I just use it to export to FBX.
When I wanted to bake node textures into images, I got an error:
Python: Traceback (most recent call last):
File “C:\Users\user\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\omni_panel\ui.py”, line 232, in draw
can_bake_poll, error_data = baker.omni_bake_maps_poll(context)
File “C:\Users\user\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\omni_panel\material_bake\baker.py”, line 387, in omni_bake_maps_poll
if not _material_can_be_baked(material):
File “C:\Users\user\AppData\Roaming\Blender Foundation\Blender\4.0\scripts\addons\omni_panel\material_bake\baker.py”, line 338, in _material_can_be_baked
outputs = output_nodes_for_engine(material.node_tree, “CYCLES”)
AttributeError: ‘NoneType’ object has no attribute ‘node_tree’