Solved Black screen upon login after KB5035853 install

Two days ago I did the March 2024 updates, including KB5035853, at the end of the day, with the computer completing a restart after installation.

The next morning I got the computer's login screen, but upon entering the correct login credentials, the screen went black. I flailed away on some keys, and something I did caused a restart, again bringing me to the login screen - with everything looking normal - but then again, logging in made the screen go black.

After another restart, I logged into a seldom-used other account I have on the computer (meant to be used if it's ever at a repair shop). That login took a while (I don't think it's ever been logged into since I went from Win10 to Win11 last year), but then I had a normal-looking desktop and functionality. I logged off of that, then logged back into my own account, and everything was normal again.

So that's good, but what happened in the first place to cause the login to send me to a black screen? And why would logging into a different account on the computer fix the problem? And if I didn't have that other account, what would I have done to fix the problem?

There must have been a bit and bob in your user profile that was misplaced during update. Something that caused the update not being able to complete the update properly.

This can be caused by many things...the list is so long that I won't bother post it all here.

Something is causing Windows Explorer to crash leading to the black screen you see.

Explorer needs to run to draw the desktop and to show the file manager.

A third party app is likely interfering with it.

Yeah, this is very possible.

NormanF said:

Something is causing Windows Explorer to crash leading to the black screen you see.

Explorer needs to run to draw the desktop and to show the file manager.

A third party app is likely interfering with it.

Click to expand...

Thanks. And in fact, I remember that when I logged into the "other" profile, I got a message saying Windows Explorer had crashed. But then, if I remember correctly, the screen built itself and then everything was good and normal.

Below are my filtered critical errors. The 41 at the top must have been my key flailing doing a forced restart. But notice that going back to November, every Wednesday after that month's updates install, I've had a 4502 - "windows recovery event servicing failed" - error. Interesting. Can anything be said about a cause for that or how to find it?

And was I "just lucky" that I eventually got my display back? Or is their a proven way to force getting it back, short of starting in safe mode?

UPDATE: I ran scf /scannow and it did fix errors. Below are the relevant lines from the logfile:

2024-03-15 09:48:52, Info DEPLOY [Pnp] Corrupt file: C:\WINDOWS\System32\drivers\BthA2dp.sys
2024-03-15 09:48:52, Info DEPLOY [Pnp] Repaired file: C:\WINDOWS\System32\drivers\BthA2dp.sys
2024-03-15 09:48:52, Info DEPLOY [Pnp] Corrupt file: C:\WINDOWS\System32\drivers\BthHfEnum.sys
2024-03-15 09:48:52, Info DEPLOY [Pnp] Repaired file: C:\WINDOWS\System32\drivers\BthHfEnum.sys
2024-03-15 09:48:52, Info DEPLOY [Pnp] Corrupt file: C:\WINDOWS\System32\drivers\bthmodem.sys
2024-03-15 09:48:52, Info DEPLOY [Pnp] Repaired file: C:\WINDOWS\System32\drivers\bthmodem.sys

Click to expand...

Comments on what might have been accomplished with these repairs?

It'e extremely doubtful those files caused your issue as sfc finds the same files for most of us. They are related to bluetooth drivers . It's been a quirky thing with sfc for quite some time now.

I have this one on all my computers too

2024-03-15 09:48:52, Info DEPLOY [Pnp] Repaired file: C:\WINDOWS\System32\drivers\bthmodem.sys

Click to expand...

Turns out that an add-on called "Explorer Patcher" was causing this problem.

Please see 23H2 black screen after logging in following 11/2024 updates for more information.