If you’d rather not, open the Avast GUI>Menu>Settings>General>Troubleshooting>Open Old Settings>Troubleshooting (in Old Settings)>Select Restore Factory Defaults.
Reboot after resetting to factory default and ensure you are connected to the Internet. As Avast updates automatically on a restart or emerging from sleep mode, best to have internet connected and this should take care of any VPS updates required. You also can manually update your VPS yourself.