Help change username

[Len]

When I try to change the username, I get this error
User names must be unique. The specified user name is already in use.
However, when searching for such a user, there is also no name.

xenForo 1.5.15a

 

[AnimeHaxor]

1. NulledTeam or Your site?

2. What is called add-on?

3. Can you take screenshot?

 

[Len]

@AnimeHaxor

 

[AnimeHaxor]

If you found user already takes a username. You can change to user_tmp,

If you still have problem, You need to enter rebuild cache, If it doesn't work, try re-install xF: http://YourSite.com/install