Latest Avast Pro Antivirus Update Shuts Down Log on!

Got the latest update for Avast Pro Antivirus yesterday. Went fine until after the suggested reboot.
Then could not log back on to my Windows 7 Professional desktop. Got message “The User Profile
Service failed on log on. User profile cannot be loaded.” What gives? Has Avast screwed up for
others, too?

Robscot 3/5/18 3:00 p.m. EST