I installed assimp using vcpkg and got irrAssimp into my project. It loads .obj just fine, but when I do .fbx the bones are completely deformed and disfigures the model:
Model in Blender:
https://i.imgur.com/46o0roK.png
Result:
https://i.imgur.com/ZXQ66nO.png
IrrAssimp and Mesh Deforming
Re: IrrAssimp and Mesh Deforming
Thats a common problem with assimp in general. Someone on the minetest project was working on GLTF support so you may want to try that out. Blender should be able to export to that without issue.