[SOLVED] Windows Update error 0x800f0831

[Meatball]

Windows 10 Pro 21H1

Hope someone can help me avoid a complete reinstall...again.

Getting the error in the title when I try to install any update in Windows update

DISM /online /check-image /restorehealth (with or without source WIM) fails with source file not found

SFC returns no errors

Attached is my CBS.log and DISM.log

 

[Meatball]

No one?

 

[Meatball]

Updated CBS.log file here:

CBS.log

Only one package cat/mum missing now - Package_for_RollupFix~31bf3856ad364e35~amd64~~19041.985.1.6.cat

 

[Maxstar]

Hi,

Download

SFCFix and save it to your desktop.

WARNING! The following fix is specific to the user's system in this thread only. No one else should follow these instructions, as it could damage your system.

• Save any work you have open, and close all programs.
• Drag the SFCFix.zip file over the SFCFix.exe executable and release it.

• SFCFix will launch, let it complete.
• Once done, a file will appear on your desktop, called SFCFix.txt.
• Post the logfile (SFCFix.txt) as attachment in your next reply.

Restart the computer and run Windows Update again. If it fails, please attach a new copy of the CBS.log.

 

[Meatball]

Windows updates are succeeding just fine now. Log attacked. Good lord, where on earth did you find that cat/mum? I went through every windows update I'd ever applied on this thing (those that I could download anyway) and deconstructed it to try and find it!

 

[Maxstar]

Hi,

Glad to hear that the problem is solved.
More detailed information about (default) cat/mum files can be found in this tutorial.