It was bound to happen at some stage, with some program. I only get to installing the first Rapture Pro update when Windows10 pops up and informs me that it's "current update is ready and would I like to set a reboot time?" This immediately froze my Rapture Pro update process and nothing I did would force it to go forward. The only option was to close CCC, allow windows to reboot, and commence the CCC update again. Fortunately CCC was smart enough to know where it was up to and continued as if it expected something like this might happen.