Live update includes 2 stages.
1) Downloading the latest definition
2) Installing the downloaded definition.
Error code 4 means that liveupdate failed to download the definition from Symantec over Interrnet.
Please follow the document at the link below and look for connection failures caused by proxy or firewall and fix it.
How to determine whether your firewall is blocking LiveUpdate
http://www.symantec.com/docs/TECH102059