Error configuring anonymous bind to LDAP directories

We have two different scenarios on this case:

• after edit a existing LDAP directory and trying to save the new configuration, without setting the user and password to bind with anonymous user, it doesn't save the changes. If we try to edit it again, to old configuration is still set.

• when trying to save a new LDAP directory without setting the user and password, to bind with anonymous user, it throws a screen error (attached).

In both cases, the "test settings" is successful.