Vimeo recently integrated some aggressive rate limiting for their oEmbed API and video detail pages. Embedly got caught up by their rate limiting and were unable to serve their embeds.
Vimeo white listed Embedly, so things are returning back to normal. Due to Embedly caching, all URLs called in the last 12 hours will continue to error till they are cleared. For cards, this is 24 hours.
You can manually clear Embedly's cache by adding force=true to your API request like so:
( This should only be done on a manual basis)
Please reach out to firstname.lastname@example.org
if you have any questions.
Shout out to Brad and Peter at Vimeo for getting us white listing.