Fact is, as I mentioned in another thread, I have had seceral newly introduced, but minor errors, that I did not have in 9841. It does not disturb me too much. This is a branch build and I live with the optimistic hope that when they bring it all together, it will perform ok. Now is the time to throw that feedback at them!
Yeah I didn't think it did the same thing with the earlier build I seem to remember running Ccleaner with no ill effect. I have quite a few images/wallpapers which are backed up and I always pop this folder in the Pictures section for easier access hence the discovery of the bug..
Ultimately though Davehc is right about that feedback!
I used CCleaner 4.19, on Build 9860 a while back. Wiped out Windows.old very nicely and didn't do anything undesirable to thumbnail pictures. Run CCleaner quite regularly, no matter what Build, always the latest version of CCleaner, no ill effects, @ all.