I'm interested in the comments here about the matter of CCleaner putting its nose into Avast when it's not wanted. With CCleaner you have a choice whether or not to include Avast. If getting rid of some , most likely, unnecessary logs which most people never see because by Avast puts them in folders Windows hides by default, then simply untick the Avast entries in the Applications > Utilities.
But the fact is CCleaner has always included Avast log cleaning by default and any other action it is capable of relating to Avast could be performed without issue until now. Avast's behaviour has apparently changed not CCleaner.