I'm using the free version of CCleaner with Firefox, and I always use Custom Clean. A few days ago it almost entirely stopped cleaning the cookies and cache from Firefox. Now after cleaning it only lists a few cookies and a few files of cache cleaned, never more than 4 of either and usually only 2 or 3. In fact I ran it just now, and it listed both cookies and cache as skipped! The first time it happened I checked in Settings >Clear Cookies and Cache and the usual amount of stuff still remained to be cleared, so now I have to clear them both manually. I'd really appreciate anything you can tell me about why this is happening and how I can fix it.
Since it's stating it skipped cleaning make sure Firefox isn't running in the background, that's typically the cause. If you installed any new addon/extension in Firefox that may cause it to keep running.
Also when closing Firefox it doesn't instantly close. Depending upon the CPU, disk speed, etc., it can take awhile to fully close before you can successfully clean it.
v5.82.8950 will list the folder "Firefox - Cookies" in Win7.
v5.83.9050 will not list the folder "Firefox - Cookies" in Win7.
The same in Win10 and Thunderbird.
@chokito This is simply a change to how CCleaner v5.83 reports cleaning Firefox (and Thunderbird which is also bt Mozilla).
It is still cleaning Firefox cookies, but mozilla have changed where and how they are stored.
See this for more details: