If you are using a tool like and seeing an error when posting an MP4, ensure you are running the latest version. Some users have reported issues where MP4s work for YouTube but fail on Facebook/Instagram unless manually uploaded or re-processed.
"A quick look at the process behind the scenes. 🎬 #WIP #Ajb08249" Ajb08249 mp4
If the file is too large (e.g., over 50MB for certain web players), try compressing it. Reducing the file size can often fix "failed to upload" errors. If you are using a tool like and