RPC Error

I have an intmitant problem with aVast! Somedays when I but up my two PCs I get a red no entry sign on the aVast system tray icon and when I double click on it I get the following message:

avast!: The AAVM subsystem detected a RPC error. The operation could not be completed.

If i restart either computer it works ok. Please help.

You have to start the Avast! Antivirus service.To go there,click the start button,settings,Control Panel,(many people do not have this option) Administrative Tools,then services.

I have the same problem:

Additionally, the following appears in the Event Viewer for Avast.
AAVM - initialization error: AavmStart: avworkInitialize failed, 0000A413.

The two Avast services I see are running.