just click on the youtube button....

this puts the youtube tags into your post....

then, using copy and paste, just copy and the address of the video you want to embed from your browser address bar when watching the video and paste it between the youtube tags in your post...

For some strange reason, the youtube address includes an extra letter which stops the video from embedding.... it's the letter 'S' that I've highlighted here in red....
https://www.youtube.com/watch?v=HDqpinCOiFs
Just delete this letter S and it'll work ok
and that's it... simple!

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