I think that's the second time you've said you are having trouble importing YouTube links...
And I think both myself and someone else (@clochette?) said the first time that all you need to do is to copy the YouTube link, and paste it directly into your reply. If that's what you are doing, and it isn't working, I'm not sure what can be wrong...
I have read that some YouTube links may be (designed to be?) non-embeddable, but if you were trying to embed the same video link I successfully shared, I fail to understand why it wouldn't embed for you.
Just a thought... you are simply pasting the link directly into the text editor, I assume. What I mean is you are not clicking on the "Link" button at the top of the editor to add the link? If you use the Link button, the YouTube link will simply appear as a clickable link, rather than rendering into displaying the actual video in your reply.
So just paste the link directly into the text area of your reply, and it should display correctly...
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Hope this helps. If not, maybe pose a question in the Help Forum. Here's one about YouTube videos from a few years ago: