I saved out formatted for youtube from premier pro - I did the 1080p, I think that was a big issue - but I wanted to make sure I maintained quality since it was a painting video..

I would try to stick with .mov or .avi - but it was very buggy with mine too - I had to try uploading 3 different times before I got the green check. I didn't change anything between uploads, I just kept re-uploading. Also, I feel like there are issues with the playback - it takes a bit of time for the videos to load. I have tried to watch several popular videos on there and I have had no luck watching an entire video because it will load, let me watch a bit then freezes again and never buffers any more. I'm sure it will get better with time.