Mixamo rigs and other rigs from other developers add mixamo: to all elements of the rig. This remove them.
https://gitlab.dzwxgames.com/deem/fbx-bone-fixer
Usage: fbxbonefixer.exe myfile.fbx <textoreplace>
example: fbxbonefixer.exe myfile.fbx “mixamo:”
requires the FBXsdk
