Lesson Learned re: KB5012599 issue: Blank desktop after apply/restart

[smsdba]

This is not a call for help, but sharing hard lessons I learned on how to work around issues caused by April 2022 KB5012599:

[2022-04 Cumulative Update for Windows 10 Version 21H1 for x64-based Systems].

[If I should have posted this somewhere else, kindly direct me there].

The symptoms after applying it & a restart:

* Logon opened to a black/blank desktop with no start menu, no icons and no ability to run any Win Key combo's.

* CNTL/ALT/DEL did open and Task Manager worked, then offering ability to run pretty much anything I had the path for [or in the Env path file].

After multiple apply/uninstall iterations of [3] KBs that were applied together, was able to isolate the issue to KB5012599.  Unfortunately, this KB runs a good long while [with my SATA HD].

After an exhaustive web search for similar issues and a few more attempts at running this KB, I found the following work around:

* After applying KB5012599/restart:

- Disable the [App Readiness] service and restart.

- For me, trying to STOP this service failed.

- To get this done from a blank desktop:

• CNTL/ALT/DEL;
• Open Task Manager; If this opens with the [Fewer details] screen, Click on [More Details]; Click on Services tab [top/right]; Click on [Open Services] hyperlink at the bottom.
• Right click on [App Readiness] service, then Properties. Under [Startup Type], select Disabled, then OK.
• Restart the OS.

BTW, I also learned that KB5012599 apparently wants the [App Readiness] service to be Automatic startup type [and presumably running during its apply process] ... I tried applying it with the service Disabled and the apply threw error:  [We couldn't complete the updates, undoing changes.... and showed error: 0x800f0922 once I got back to the Win Update screen] ...  which of course involved more endless hypnosis watching Microsoft's little spinning wheel.

Not sure if that service needs to be Automatic and/or running for other KB applies or not.  I'll be trying it next time Windows 10 FORCES me to apply subsequent updates in the future.

Hope this helps anyone facing this problem.

My system: HP Z2 Mini G4 Workstation, Windows 10 Pro, Version 10.0.19043, 32GB RAM, Intel Core i7-8700

[FisherHU]

Thank you for the solution, I owe you a beer 🙂