Board Thread:Support Requests - Getting Technical/@comment-5454372-20130821210553/@comment-5558012-20130822180223

Is this the only instance?

I don't know exactly why, but did you try reverting the move, deleting the user (if it still exists), and renaming the blog before renaming back into the User blog namespace?

If this doesn't work, I don't know what else you could do besides reporting this to Wiki staff.