Same here, I am getting this error on 3 different computers! My Win 7 64-bit SP1 desktop and (recently re-imaged) laptop, and my mom's Win 10 64-bit laptop which has no other 3rd party security software on it.
I found something interesting. When I booted up my laptop after updating Avast, the icon was normal, suggesting all was well. Then, Comodo Firewall told me avastui, wanted to connect to the internet, which I allowed. The moment the connection was established, avast donned the Red X of Doom! and all was not well. Hmm.