The reason the urls don't convert is that there are hidden characters on the ends of them that mess with the parser, which (rightly so) refuses to parse them as links.
It's possible your copy / paste carried across some formatting code. If you re-type the urls they all work.
Update: I removed all the formatting code. The links work now. I don't recommend copy / pasting already formatted code from websites in the future though, especially from heavily scripted sites like YouTube.
It's possible your copy / paste carried across some formatting code. If you re-type the urls they all work.
Update: I removed all the formatting code. The links work now. I don't recommend copy / pasting already formatted code from websites in the future though, especially from heavily scripted sites like YouTube.