[Satellite 6] Login to satellite with LDAP user fails with error "Oops, we're sorry but something went wrong / undefined method `each' for nil:NilClass"

Issue

• When trying to login satellite webui with LDAP user it fails with error:

Oops, we're sorry but something went wrong
undefined method `each' for nil:NilClass
If you feel this is an error with Satellite 6 itself, please open a new issue with Satellite ticketing system, You would probably need to attach the Full trace and relevant log entries.
NoMethodError
undefined method `each' for nil:NilClass
app/models/auth_sources/auth_source_ldap.rb:103:in `update_usergroups'
app/models/user.rb:197:in `block in try_to_login'
app/models/concerns/foreman/thread_session.rb:73:in `as'
app/models/concerns/foreman/thread_session.rb:79:in `as_anonymous_admin'
app/models/user.rb:191:in `try_to_login'
app/controllers/users_controller.rb:71:in `login'
app/models/concerns/foreman/thread_session.rb:33:in `clear_thread'
lib/middleware/catch_json_parse_errors.rb:9:in `call'