Insert from URLThe video to embed as usual
(Image link: http://cld.wthms.co/oVgPKx )
The following error is shown Sorry, we can鈥檛 load the video at the supplied URL. Please check that the URL is for a supported video file (.mp4, .m4v, .webm, .ogv, .flv) or stream (e.g. YouTube and Vimeo).
(Image link: http://cld.wthms.co/qByLvM )
Reported in #1664494-Zen
Reproduced on my own test site. If I disable Gutenberg the video embed works
Similar issue reported and fixed here: https://github.com/Automattic/wp-calypso/issues/25195
As in this reported issue if I try to embed the video through a Text Widget it works.
#user-report if applicable.
Reported here as well: 7445995-hc
Reported here: 1724157-zen
Reported here for Vimeo: 1914085-zen
This is not an issue anymore. I am able to add an YouTube video by URL option, on the Video widget on Customizer just fine. Could you try again with your respective sites/check with your users' on the situation, @sarahfg, @jamiepalatnik and @ezebecke?

@ahmadbaig1 Your situation seems to be very different in that yours being a Vimeo block itself. Could you search for a related issue/create one afresh, please? Thanks!
Works for me in my test now, thanks!
Works for me on my test site :-). I've followed up with the user that reported it letting them know it's resolved.
That's good to know! @ezebecke, I see your ticket was in Spanish. If you could followup, that would be amazing. Thank you!
Closing as resolved.
Thanks @arunsathiya. I have followed up with the user.
Most helpful comment
This is not an issue anymore. I am able to add an YouTube video by URL option, on the
Videowidget on Customizer just fine. Could you try again with your respective sites/check with your users' on the situation, @sarahfg, @jamiepalatnik and @ezebecke?@ahmadbaig1 Your situation seems to be very different in that yours being a Vimeo block itself. Could you search for a related issue/create one afresh, please? Thanks!