Since upgrade I cant embed YouTube links anywhere. I mean, removing the automatic embed and just show links work, but whenever the automatic embed occurs and the video shows I cant save that post, download or whatever. It just loops back into edit mode and can't be saved until I convert the embed into a raw link.

I have now installed a fresh test installation and the problem occurs even there. Fresh database, fresh install, no plugins, no themes.

Support ticket with documented steps to reproduce.  

OK thanks