CCleaner for Mac crashes all the time, gets 'closed unexpectedly' error message in CCleaner for Mac Posted March 12 Sorry I can't help, but someone should respond. I posted a similar complaint or question in January and no one replied. Is anyone on this board? Anyway, on my MacBook Pro running High Sierra and the latest CCleaner version (same as yours) it opens and runs up to 26% completion and freezes every time. I've uninstalled it, reinstalled it, tried three different browsers, always with the same result. Judging by all the problems for Macs, I think maybe Ccleaner just doesn't care to optimize Ccleaner for Macs. I suppose it's time to look for another product. Good luck with your question. I hope you have better luck getting an answer.