I'm using blender to construct a model with assigned materials in it. I'm then exporting that model as an .fbx file so that I can upload it to mixamo. Unfortunately, the .fbx file mixamo returns back to me is without the original materials because as far as I understand, mixamo uses an older FBX version than what blender currently uses, so all the materials are lost on import into their system. When I open mixamo's exported fbx file in blender again, all the material data is lost.
I'm wondering if there is a way to use blender's append feature to append the materials from the original blend file into the new fbx file mixamo exported for me, and automatically reassign them to the faces, since none of the geometry in the core model has been changed? If not, are there any other options available to me? I've attempted to download a 2015 version of blender to try and export the model in an older, compatible fbx version that mixamo supports, but blender crashes as soon as I try to open the blend file. Is there an open source/free fbx down-grader? Thanks ahead of time for any help?