LDAP no longer let user login

Steps to reproduce

Login with a existing user account from LDAP.

What is the current bug behavior?

Access denied for your LDAP account.

What is the expected correct behavior?

Let the user connect.

Relevant logs and/or screenshots

(LDAP) Error saving user LDAP_PATH (temp-email-for-oauth-USERID@gitlab.localhost): ["Email has already been taken"]"

Output of checks

It wasn’t an issue before the update to 16.6.0. We used 16.3.4 before. I tried to revert back and same issue. All user except the default admin user can’t login anymore :frowning: .