# “Internal error setting the array” during FBX export

I am trying to export a 3D model from blender 2.81 to an FBX file. After clicking 'Export FBX', I receive the following error:

Traceback (most recent call last):
File "C:Program Files\Blender Foundation\Blender 2.81\2.81\scripts\addons\io_scene_fbx\_init_.py", line 634, in execute
return export_fbx_bin.save(self, context, **keywords)
File "C:Program Files\Blender Foundation\Blender 2.81\2.81\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 3198, in save
ret = save_single(operator, context.scene, depsgraph, filepath, **kwargs_mod)
File "C:Program Files\Blender Foundation\Blender 2.81\2.81\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 3094, in save_single
fbx_objects_elements(root, scene_data)
File "C:Program Files\Blender Foundation\Blender 2.81\2.81\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 2894, in fbx_objects_elements
fbx_data_mesh_elements(objects, me_obj, scene_data, done_meshes)
File "C:Program Files\Blender Foundation\Blender 2.81\2.81\scripts\addons\io_scene_fbx\export_fbx_bin.py", line 1163, in fbx_data_mesh_elements
uvlayer.data.foreach_get("uv", t_luv)
RuntimeError: internal error setting the array

location: <unknown location>:-1


This is a .blend file I got from someone else. The only change made was to separate part of one of the meshes into its own mesh. Initially, it exported to FBX with no problem. When I went back and separated another mesh, saved, and tried to export to FBX, it started giving me this error.

I'm new to 3D modeling and blender, I have no idea what any of this code stuff means. I've tried googling this error and I'm seeing a lot of "nevermind, fixed it" type responses without explaining what they did to fix it. Thanks in advance!