LDAP error message in log

Nextcloud version: 22.1.1
Operating system and version: Ubuntu 20.04.3 LTS
Apache or nginx version: Apache/2.4.41
PHP version: 7.4

Hello everyone,

I keep getting the following error message in the log (mostly at night).


I’ve been looking a little, but can’t find anything about it. Where exactly can I find the LDAP log? Or do I have to activate it first?

thank you for your help