I have made about 20 YouTube videos each producing an URL on the form www.youtu.be/…
that was equivalent to the same URL but with www.youtube.com/…
.
I produced QR codes based on the former URLs and have published these in my book which was published last autumn (Oct 2012). Now the youtu.be URLs no longer work (why??), but the similar youtube.com URLs are OK.
How can I make the youtu.be URLs work again (otherwise I would have to produce new QR codes, which is problematic as the other ones are published in a book).