Sometimes when embedding a video, you may run into the error "Sorry, we cannot use this video for embedding".
In this situation there are a few things to check:
1. Make sure that you are embedding a video, not a playlist and not a channel
When embedding a video from YouTube and Vimeo, ensure that you are embedding the video itself and not a channel or a playlist.
For example, for YouTube videos the URL you paste in should be in this format: https://www.youtube.com/watch?v=frdj1zb9sMY
2. Make sure that the privacy and embed settings are correct
On both YouTube and Vimeo you can set the video to not be embeddable. Check the settings to ensure that the video is publicly viewable and can be embedded on external websites.
3. If you just published the video, you might have to wait
If the above all looks correct, then wait a few hours and try again. Unfortunately, we have run into the problem where a recently published video is unable to be embedded because YouTube's API returns an error - in this case, the fault is with YouTube and we just have to wait for their API to return the correct information.