LoginLdap (v4.0.3) / Warning - ldap_bind()


I installed Matomo 3.3.0 and the LoginLdap Plugin, v4.0.3.
The Ldap Plugin works fine, nevertheless, the following warning appears each time a user logs in:

WARNING: /var/www/htdocs/piwik/plugins/LoginLdap/Ldap/Client.php(91): Warning - ldap_bind(): Unable to bind to server: Inappropriate authentication - Matomo 3.3.0

A colleague and me, we checked the LDAP Settings and couldn’t find an error.
Has anyone an idea what is wrong here?

Thanks in advance.


I know little about Ldap, but the error comes from the PHP function that tries to connect to your server.
So maybe start there with the debugging.