"Sorry, unable to map your existing skeleton" on a model after Blender export as FBX
I have this FBX model:
When I upload this into Mixamo, it works out of the box.
But when I import the fbx into Blender and (do some changes, or even not) and export it as FBX and try to upload on Mixamo, I get that error.
Maybe I am doing something wrong on the export from Blender - since it is the same model and structure and polygons it should work.

I saw I am not the only one here, but I checked some stuff like not using metal in shaders..
what could it be? can someone try it "quickly" (I really appreciate it! <3)
