I also just downloaded the newest version today: 5.43.6522 , 64 bit and the problem persists. I am running Windows 10 version 1803.
I am really disappointed as I have used CCleaner for years!
I have found this to be the case as well. I disabled Kaspersky, uninstalled 5.42 then reinstalled 5.43, rebooted etc. Still not working. Closes immediately after selecting "run cleaner". Using Windows 10.