LIVEUPDATE

 I am running SEPM 12.1 version on a Server 2008 R2 platform. We have both XP and Windows 7 platforms clients.  

Recently, the SEPM has stopped updating.  The client machines have also stopped receiving updates from the SEPM.  Proxy setting are correct and there is connection to the sePM Server.  

I have tried all the solutions placed on these forums and your website. I have reinstalled the Liveupate, run the Lucatalog -cleanup and -update, but thus far nothing has worked.  I keep getting the error - Liveupdate encountered one or more errors. Return code = 4.

Please helps as we have nearly 170 machines, and we have to update them manually as this is the only way to do right now.