When I go to upload a specific avatar body I run into this issue during the submission process in studio:
All of the body parts are validated through Avatar Setup and the upload process, but it errors at step 2 of 4. I have tried everything from redoing the cage, UVs, verifying it has no bad geometry, etc. but troubleshooting has become impossible because the error message is unspecific. Output doesn’t have any message either.
After hours and hours of troubleshooting I was able to confirm it was an issue with the face.
Seems as though the in studio validation process is different than the actual upload validation process. I was able to get through a version of my avatar body where in the face deforms significantly more than the original version.
This was version 1, where the face animated but the head did not. It passes the avatar approval check as you can see in the top left, but the submission fails for the above error when uploading.
Version 48 that I made today has the whole head animating along with the mouth. It is approved both in studio and via the upload process.