It is to do with new Windows Patches, Piriform has not prepared for.
As soon as I remove Edge and Internet Explorer from the cleaning, it works, i.e. CCleaner does not crash and cleans Chrome and Opera.
I am using pro 5.39.6399 ( 64 bit ).
So it has to do with a new protocol in Windows.
If I debug using Visual Studio it says it cannot find :
C:\Windows\System32\msvcrt.dll
So Piriform has obviously used this dll in the past, Microsoft got rid of it ( who knows why ) and Piriform has been caught unawares.
Please sort this out Piriform, as it is pretty useless for your product to work on only some browsers...especially as a paying customer.
Thank you.,