Has any headway on a resolution been made on this by Avast? I just started having this problem as well. It is a major inconvenience. I am running version 4.6.15 of Clean My Mac, version 14.6 of Avast, and version 10.15.7 of MacOS. Avast consistently wants to put certain PUP files related to Clean My Mac in the virus chest. If I allow this, Clean My Mac will no longer boot and I have to reinstall it. Avast allows for an exception to be set but the exception process is ineffective in getting Avast to quit interfering with Clean My Mac.