See this KB with a possible solution -
"Error: LiveUpdate encountered one or more errors. Return code = 4" in LiveUpdate status in Symantec Endpoint Protection Manager
http://www.symantec.com/business/support/index?page=content&id=TECH103112&actp=search&viewlocale=en_US&searchid=1291053162137
This article may also be helpful,
Troubleshooting LiveUpdate Issues with Symantec Endpoint protection
https://www-secure.symantec.com/connect/articles/troubleshooting-liveupdate-issues