Hello,
A Duplicate Thread to :
https://www-secure.symantec.com/connect/forums/sepm-12-error
Could you please let us know -
1) What OS are you running on the SEPM server?
2) Were there any changes made on the server like firewall, proxy, etc?
3) Are the clients able to communicate with SEPM server?
4) What happens if you run the Liveupdate from the SEPM console?
As per the screenshot, what I see is SEPM is updated, however the clients are not updated.
To know the Latest Definitions - http://www.symantec.com/security_response/definitions.jsp
Troubleshooting Articles:
1) Symantec Endpoint Protection Manager 12.1 Communication Troubleshooting
http://www.symantec.com/docs/TECH160964
2) Troubleshooting communication problems between the management server and the client
http://www.symantec.com/docs/HOWTO55017
Secondly, could you please upload the sylink.log from 1 of the client machines which is not updating.
To collect the sylink.log, http://www.symantec.com/docs/TECH104758
Hope that helps!!