Could be a few things. First, you'll need to be streaming during the submission process, streaming something. Otherwise Roku see's it as no video. Even stream a simple graphic. Generally speaking, Roku doesn't accept redirects, which is why Youtube cannot be used as a host (in addition to possible TOS). I don't know about their Livestream urls tho, which leads me to point three. Third, there is a separate section for Direct Publisher, seen here: https://community.roku.com/t5/Roku-Direct-Publisher/bd-p/roku-direct-publisher I would try searching there & posting there. Search those error codes and/or Vimeo Livestream and such.
Have you tried finding the URL it redirects to, and using that instead?
Thanks,
I was streaming some test video when I was working on this but I'll try again to make sure 100% it's coming through.
Also thanks for the link to the other community I'll check there.
I thought about just using the redirect URL's but those should only be valid for a couple hours then they change to prevent theft which is why Vimeo switched to redirect links.