You already have someone mentioning virtualization stopped working, for me it was worst, the virtualization worked right away when starting the system and then it was disabled after some minutes (5-13 not sure), so I got BSDs when I had the virtual machines open at the start of the system with either virtualbox or vmware.
My system is ryzen 7 1800X, windows 10 64 bit fully updated.
This is not the first time I have had stability issues like this, so for now I'll stay away from avast and will probably buy something else. I thank you anyway for the great free product which I'll keep recommending to people that uses their pc for less things.