System Diagnostic - Check for problems with UDN replication - Listener Error?


In our primary UCS system diagnostic module, we are getting a warning about “Check for problems with UDN replication”. After running the command in KB 11811 “/usr/lib/nagios/plugins/check_univention_replication”, we get the response “CRITICAL: no change of listener transaction id for last 0 checks (nid=Error: [Errno 111] Connection refused lid=cat: /var/lib/univention-directory-listener/notifier_id: No such file or directory)”.

/var/log/univention/notifier.log seems to show no errors, however /var/log/univention/listener.log shows the error:

connection to server failed with errorcode 111: Connection refused
failed to connect to any notifier
can not connect any server, retrying in 30 seconds

Not sure why the connection is being refused, any suggestions?