Why have my Yahoo groups disappeared?

Question

I had 14 Yahoo groups and for some reason all but one are gone.

Answer 1

Yahoo is doing maintenance

http://www.ygroupsblog.com/blog/

generally always glitches during it

Answer 2

When I noticed a lot of my groups were missing, I searched for one of them and clicked the link to go to its page. I got an error message that said Yahoo couldn't complete my request but they were aware of the problem and working on it. So I expect that once they fix the problem, the missing groups will reappear.