Fixed. All fresh installations are OK from now on.
For existing affected users, fastest way to fix it is to run C:\Program Files\AVAST Software\Avast\AvastEmUpdate.exe and then reboot. Others are getting the fix anyway, it just takes some time.
Sorry for being so brief, we were working hard to get the fix in the production ASAP. You were protected the whole time. The issue was in the GUI - it did not know Avast service is in fact running.
Thanks for your patience,
Petr