Last modified: 2010-03-01 21:03:12 UTC
If you have a user named '0', their groups cannot be changed through [[Special:UserRights]]. * Entering '0' as the username behaves as though no user parameter was supplied * Entering the user's ID prefixed by a #, which works for other users, gives the error "You have not specified a valid user name."
Fixed in r63135.