[ccleaner doesnt clear firefox]

Unchecking Session did not work for me.  Consistently 6 files remaining uncleaned.  What does excluding a file do?

[Last FF bookmarks and history are gone after cleaning]

 

I've narrowed it down futher now.

 

The culprit is-

C:\Users\{username}\AppData\Roaming\Mozilla\Firefox\Profiles\{profilename}\sessionCheckpoints.json

 

Deleting this file causes FF56 to open with 'restore tabs' rather than opening with your homepage, no matter what your FF setting is.

 

It looks like FF56 is now storing your startup preference in this file instead of where it was stored in earlier versions.

(So if the file is not there it reverts to the default 'restore tabs').

 

You could make this file an exception in CCleaner rather than unticking Firefox 'sessions' in the cleaner.

 

 

 

Running CCleaner on 2 machines.  Experiencing the some of same things on one machine and some on the other.  History is gone on one machine.  Favorites tabs are gone.  Bookmarks are gone on one machine. 

Exploring the FF session shows 6 folders that will not clean.  The address is similar to the one posted above, but not exactly. 

 

  Could someone give me step by step instructions?...and do it as if explaining it to a computer illiterate, which I am. 

[Firefox vers 56 History not cleaning]

Same here.  Have the latest  CCleaner installed but FF is not cleaning entirely.