XF 2.1 Change Username Error - "was previously used by another user"


Well-known member
Hey All!

I want to give a newer member the username of an inactive / old member with no posts.

In the past, it seems this worked:
  1. "UserA" exists
  2. "UserB" exists
  3. Change "UserA" to "UserA-OLD"
  4. Change "UserB" to "UserA"

So, I tried that process and got this error:

Oops! We ran into some problems.
  • Please enter another name. The specified user name was previously used by another user.
  • Please enter a valid name.
Any ideas why this isn't working and/or what I can do to give this newer member the old member's username?

Seems that once the old username is changed, it should be available to associate with a different account, no?

Chris D

XenForo developer
Staff member
Is this XF 2.2 or XF 2.1?

I don't recognise that error message, exactly, and this functionality isn't something we added until XF 2.2.

I suspect you may have an add-on in XF 2.1 so you would have to report that to the author.

I haven't tested it, but I'm pretty sure you wouldn't run into this in XF 2.2 assuming you are an admin who is changing the username from the admin control panel.


Well-known member
Thanks for the quick reply @Chris D !

I'm on XF 2.1.11

I hadn't even considered it being an addon issue. Hmm..

The only thing I can think of is maybe @Xon User Essentials 3.6.2 or his User Mentions Improvements 2.7.0

... I don't see any other addons that I would think would be impacting usernames.

I guess I could try disabling those addons and giving it a try.


Well-known member
DOH! Sorry guys!

Thanks for the help!

I guess the silver-lining is now hopefully when someone does a Google or XF search (like I did) for the phrase "specified user name was previously used by another user", this thread will come up.