Meta couldn't accept that file - try a smaller or differently formatted one.
Uploading a sample image, video, or document for a template's header failed on Meta's side. Try a smaller or differently formatted file.
Try a smaller version of the file.
Try a different, commonly supported format.
Upload the file again.
If it keeps happening, contact support at hello@theavoxai.com with this code.
Still stuck? Send AVX-3028 to hello@theavoxai.com along with what you were doing when it happened.