I have a pretty modified image and as often happens with these modified installs I eventually had problems installing CUs. Yes, I also ran cleanup and rebase. My build was locked at 18362.53 and none of the typical fixes had any impact: SCF DISM.exe /Online /Cleanup-Image /RestoreHealth <- even specifying the original source WIM in place upgrade install Everything would fail with the typical errors that point you right back to the above 'fixes'. On a hunch I decided to build a WIM specific to the 18362.53 which meant integrating KB4495666. Aside from the CU I included the other current updates (accidentally included 1909 enablement but I don't think that matters), I did not use the 'cleanup image' option. I then used the following command to repair my install: Dism /online /cleanup-image /restorehealth /Source:WIM:C:\Install.wim:1 /limitaccess Using the same WIM file I did an in place install and allowed windows to get updates. Well I be damned, it worked. On reboot I am on 18363.356. Sure, a lot of annoying steps but some of us are kind of stubborn and like to fix things as is instead of reinstalling.