Adding my 2 cents worth.... Win7, 64 bit; CC v.5.10.5373. After years of using CCleaner problem-free I have now received a "crash" three times since yesterday. One NOTE: when attempting to send a crash report the crash report window either sends or disappears before I am done entering information into the window.
Further info: whether it has anything to do with CC's crashes or not (I suspect not) the only "unusual" activity I've done on my PC of late is to uninstall / re-uninstall some of Windows Win10 related windows updates -- rebooting my PC between each un-installation. (Specifically, KB2952664, KB2990214, KB3035583, KB3021917, KB3083710.)
One QUESTION: should I not worry about it, wait for Piriform's next CC update, or uninstall/reinstall CC? (Once past the crash window CC DOES seem to run a-OK.)