This change to the ldap plugin made it work in LDAPServer.php:
- $this->con = ldap_connect($ldap_host, qa_opt('ldap_login_port')) or die ("Could not connect to $ldap_host host.");
+ $this->con = ldap_connect($ldap_host.':'.qa_opt('ldap_login_port')) or die ("Could not connect to $ldap_host host.");
I found this in the comments section of PHP: ldap_connect - Manual. The change is to pass one argument (host:port) instead of two (host, port). Ideally, both methods should have worked. Don't know why it isn't. I'm happy this is working now and haven't dug further.