Everything was working fine and all of a sudden ldap authentication stops working with the following warning.

Warning!

Could not bind to Posix user domain\user@

Here's the full trace.

LdapFluff::Generic::UnauthenticatedException
Could not bind to Posix user domain\user
app/models/auth_sources/auth_source_ldap.rb:50:in `authenticate'
app/models/user.rb:186:in `try_to_login'
app/controllers/users_controller.rb:71:in `login'
app/controllers/concerns/application_shared.rb:13:in `set_timezone'
app/models/concerns/foreman/thread_session.rb:32:in `clear_thread'
lib/middleware/catch_json_parse_errors.rb:9:in `call'

I tried solving it but i have no idea what's going on although all the settings stayed same and nothing changed.
Any suggestions is appreciated.
Thanks