Unable to establish connection with the agent after Upgrade Desktop Central to 10.1.2121.4

Unable to establish connection with the agent after Upgrade Desktop Central to 10.1.2121.4

I upgrade desktop central to 10.1.2121.4
After that I have a problem in Remote Connection
Suddenly Agent Connection Failed and agent is not Reachable
I installed servicedesk plus and desktop central on separate sever
and i integrate servicedesk plus and desktop central

remote connection doesn't work