After few test i found that the process breaks when staff user have the auth backend set to local.Tests:LDAP plugin enableChange User setting to local backend -> failChange User setting to User with all backends -> workNew user, backend set to Local -> failNew user, backend set to any -> workLDAP plugin disabledChange User setting to local backend -> failsChange User setting to User with all backends -> workNew user, backend set to Local -> failNew user, backend set to any -> worki think something is wrong with fix authbackend instead of set it to use any backend. Sorry i had no time to dig deeper into it.