CCleaner Won't Launch in CCleaner for Mac Posted November 3, 2013 CCleaner hasn't launched for me for quite some months. I didn't know there were forums, I've tried contacting Piriform via Twitter quite a few times but didn't get a response. I keep getting the message that "CCleaner has quit unexpectedly" whenever I try to open the application, regardless of whether it's the one downloaded from the Piriform website or if it's from the App Store. This has been happening on Mountain Lion as well as Mavericks, and I definitely have the updated version because I tried uninstalling and re-installing with the latest version again today. Courier New is definitely on my system and is definitely enabled. Would be nice if this could be sorted. I was planning on buying the Professional version to support the devs as I've been using this app since my Windows days, but I'm not prepared to do so if it's not going to even launch.