The unexpected HTTP code '403' was received on the HTTP request to the agent at 'https://192.168.2.240:8443/agent.cgi'.2014-01-29T21:48:19+01:00 DEBUG (7) [dbquery]:  SQL: delete from sessions where sess_id="40911befbd46693aefd5c58e4360bc28" 2014-01-29T21:48:19+01:00 DEBUG (7) [dbquery]:  END: 0.00016093254089355 sec
Releasing semaphore 4 in request cleanup
After agent was upgraded on service nodes, and old instance has left running, therefore communication between management node and a service node breaks.
Restart the following services on a problem service node (IP address should be gotten from the initial error):
/etc/init.d/sw-cp-server stop Stopping sw-cp-serverd: [ OK ] /etc/init.d/sw-cp-server start Starting sw-cp-serverd: [ OK ] /etc/init.d/pem restart Stopping pleskd: [ OK ] Starting pleskd: [ OK ] /etc/init.d/plesk-agent restart Stopping agent.cgi: [ OK ] Starting agent.cgi: [ OK ]