After signing up for CClean Pro and activating, I ran a number of programs:
Healthcheck, Performance Optimizer, Custom Clean, Driver Updater, and Registry.
I have been using the free CCleaner application for a number of years.
This time with CCleaner Pro, however, I seem to have damaged two of my four browsers:
Brave and Firefox. If I leave the browser temporarily to do another task, when I return,
the browser has become unresponsive. Sometimes the tabs that are already open will work,
sometimes not. New tabs typically do not work. Sometimes they'll say "Crash" if I hover
the cursor; mostly they refuse to accept a new URL by simply blanking it out. Do you
suppose Performance Optimization caused this by forcing a necessary background process
to sleep????? ... or what? I stopped all Brave processes, uninstalled it, and then
went looking for any leftover folders and files. I deleted them all until there was no
trace. Also ran the register cleanup. Then I reinstalled Brave. Same thing. Still
doesn't work. I have to kill it and restart all the tabs I was working on.
Google Chrome / Chromium Based Browsers:
As for all Chromium based browsers it nuked Comodo Dragon so bad (over a decade ago on my old XP PC) it never worked correct afterwards and even a clean re-install didn't work. I found out that certain browser profile folders located in sub-folders named 'Extension State' and 'Local Extension Settings' had to be excluded. I exclude both whole folder locations in any Chromium browsers profile folder after the Comodo Dragon incident and it hasn't broken a Chromium based browser since then for 12 years. They can be excluded in CCleaner at 'Options > Exclude'.
Example using Microsoft Edge Chromium I exclude these two paths (in Windows 10):
* C:\Users\UserProfileName\AppData\Local\Microsoft\Edge\User Data\Default\<strong><span style="color:#c0392b;">Extension State</span></strong>
* C:\Users\UserProfileName\AppData\Local\Microsoft\Edge\User Data\Default\<strong><span style="color:#c0392b;">Local Extension Settings</span></strong>
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Mozilla Firefox / Firefox Based Browsers:
This info is many years old however after having it brick a Firefox profile I always have these disabled/unticked in CCleaner under the Firefox section so that it never cleans them:
* <strong><span style="color:#c0392b;">Session</span></strong>
* <span style="color:#c0392b;"><strong>Site Preferences</strong></span> (this is possibly the most important one)
I also have it exclude various things in Firefox (Firefox Portable ESR is what I use), this is primarily because of what I mentioned in the Chromium based browsers comment for paranoia's sake - now rather these are necessary in Firefox I don't know, but I'm not taking any chances:
..\PortableApps\FirefoxPortableESR\Data\profile\*\|<span style="color:#c0392b;"><strong>*.sqlite-shm</strong></span>;<span style="color:#c0392b;"><strong>*.sqlite-wal</strong></span>
..\PortableApps\FirefoxPortableESR\Data\profile\<span style="color:#c0392b;"><strong>browser-extension-data</strong></span>
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Edit:
If you use the community Winapp2.ini file (https://community.ccleaner.com/topic/32310-winapp2ini-additions/#comments) that might possibly clean too much.
Edit 2:
You must use Custom Clean in CCleaner in order for it to honor exclusions, and not clean what you've disabled/unticked! If you have it just automatically clean it doesn't use any user preferences.