You got it @joshpeterson I posted 2 videos today one at 480p and one at 720p, I had just posted one tag and both videos uploaded and are playing without buffering on my phone.
The one thing you have to remember is you can only put 4 tags, as dtube will automatically add the dtube tag. If you put 5 tags you may get that same error as noted in my screenshot.
@steem-untalented