Just ran across this and not sure if it's an error or if I'm doing something wrong.
Trying to upload an mp4 manually from my computer into the uploader. After it finishes loading it gives an error message:
"Upload failed: File is not an image or video."
For context if that's necessary, tried to upload a longer, uncensored version of post #5779009 (nsfw). The artist had it as a limited timed free gumroad download so I figured it was fair game.