If you have trouble with client and server communication, you should first check to make sure that there are no network problems. You should also check network connectivity before you call Symantec Technical Support.
You can check the communication between the client and the management server in several ways.
Table: Checking the connection between the management server and the client
What to check
Look on the client to see if the client connects to the management server
You can download and view the troubleshooting file on the client to verify the communication settings.
Check that the management server uses the correct server certificate
If you reinstalled Symantec Endpoint Protection Manager, check that the correct server certificate was applied. If the management server uses a different server certificate, the server still downloads content, but the client cannot read the content. If the management server uses the wrong server certificate, you must update it.