On 5th December, my Windows 10 Pro updated to 1803. This resulted a long list of malfunctions due to changes in the OS. I.e. lost all network shares, lost the network printer, lost .PNG viewer .....
On the same day, I updated CCleaner to V-5.50.
My problem is that CCleaner now generates multiple Windows Defender notifications that CCleaner is being blocked from making changes to memory. Is this V-5.50 or 1803, as I've not had this problem before?
Same Issue here Just started yesterday 5/28
Keep Getting Same Notification Ccleaner Making Changes to Memory and Being Blocked
This is from 2018 and was a short lived issue with Defender when Win 10 updated to 1803.
Has you Windows also just been updated?
Win 10 21H1 is rolling out automatically at the moment.
Try going to Windows settings and doing a check for updates to make sure that Defender is up to date.
I've not had problems with 21H1, but a couple of recent posts may point to something happening for some users because of it.