Start10 has always been reliable on my system, but today my system installed some Windows updates and Start10 isn't replacing the Windows 10 default start menu.

I don't have Classic Shell or anything like that installed concurrently. 

I am running Start10 latest version -- 1.07 I think. I updated to version 1.07 in a prior reboot, so this most recent reboot had nothing to do with Start10 updating itself. 

I can launch the Start10 configuration application and it works fine, but the actual Start10 menu won't display.

The only Windows Update that was installed when I rebooted was KB3116900, which is apparently a massive mystery patch that brings us to a new build of Windows. http://www.infoworld.com/article/3013054/microsoft-windows/microsoft-issues-patch-kb-3116900-moves-windows-10-to-build-1058629.html