Seems every time avast! releases a major upgrade to a newer version 4.8 to now, 9.0, some avast! users have issues with that newest version.
No, this is not an attempt to blame the users; this is clearly not the case. It is just that major upgrades are not the same thing as doing an updated version within the gui, and while some have taken care to do a clean install knowing this is a major upgrade, they are still having issues anyway. So, for users that are affected, and have done what they could, know that Avast! has a multitude of service tickets pending and user system configurations to look at and resolve.
Avast! is aware of these issues, and are doing everything they can to fix them. A possible release of these fixes could happen as soon as this Friday, if all testing works out.
Workarounds are being posted here as we find and discover them; this will ensure protection with the latest version continues until a permanent fix(es) are found and released.