Here is a strange one: 

A user reports

"I got the message “The specified username is currently inactive. If you have problems activating your account, please contact a board administrator.”

In any case would like to get account reactivated."

I looked at the user's Joomla profile (CommunityBuilder) and it was normal and active.

I looked at the users's CJforum user, and it was normal and active.

I tried logging in as the user, and I did not get any message.

Is there a corejoomla 'inactive user feature"? Is there a setting for that (I hadn't noticed one...).

We do not want users to ever expire!