2 issues.
1) The sign in to the CCleaner site to attempt to get assistance gives just "Something went wrong" and links back to the zero help "Q&A" page.
2) Unable to resolve without GENUINE support for CCleaner Professional issue is this program stopper message when trying to use it:
"CCleaner is unable to clean 'Session' because application 'pre-launching' and 'tab preloading' are enabled in Windows", No such settings exist. Specific assistance required but apparently CCleaner has arranged for none to available.