A few forum members noticed that embedded Youtube videos had stopped working. I have now fixed this so they should once again work as expected: please let me know (either here or by PM) if that's not the case.
Videos in existing posts may not work and may need to be edited in order to make them reappear. If yours is affected and you can't edit it yourself, the quickest way to resolve it is to report it with a short message indicating it concerns a missing video and one of the moderators will sort it out for you.