XF 1.3 Error when changing staffs names

[williams1997]

problem again for when i try to change a admins name

 

[Amaury]

Disable all add-ons and see if the error persists.

 

[rdn]

Related to addon of Rigel.
Some addons here: https://xenforo.com/community/resources/authors/rigel-kentaurus.301/
Might be this one: https://xenforo.com/community/resources/change-username.269/