YouTube or Vimeo video does not work.

If you want to embed videos from external services like YouTube or Vimeo but instead of the video preview, you get the black screen with YT play button and after click on this button, you receive the message like "An error occurred. Please try again later."
youtube or vimeo video id
means that you have made one of the following mistakes:
  • Wrong Video ID - make sure, the VIDEO ID you put into item field is correct. If you are not sure, try to open video in Youtube service.
  • Video URL instead of ID - please check if you did not pasted complete video url instead of ID. This is the most common reason the video not being displayed.
For YouTube video, ID is a string of characters starting after ?v=
In the case of Vimeo service, it looks very similar, but the video ID starts after the slash
vimeo video id