Click Start, then Run.
Type cmd, then click OK. This will bring up a command prompt.
At the command prompt type cd and the path to lucatalog.exe. By default the command would be:
cd C:\Program Files\Symantec\Symantec Endpoint Protection Manager\bin
Type lucatalog.exe -cleanup
Wait for the process to complete.
Then type lucatalog.exe -update
Restart SEPM.
Run liveupdate once again..