Cumulative update December 2020 - KB4592438 Failed to install

I had tried DISM and SFC, standalones to no effect.

What worked was uninstalling the 20H2 enablement (KB4562830) and then using the 20H2 MCT and doing the in-place upgrade.

19042.685 installed.

Hello,

I've had problems with this update as well. I've tried enabling .NET in Windows features, disabling firewall, clearing Software distribution folder and one other in System32, those didn't help me.

After that I did the mentioned:

sfc /scannow

dism /online /cleanup-image /restorehealth

and added

chkdsk /r

But what most likely helped me was "freeing" disk space. When I was googling for possible issues for this update I've found this thread and some general info that, among others, having not enough disk space might be an issue. I've had plenty so I have ignored that at first, but after a while I have recalled I'm using 4GB RAMdisk and my both Windows TEMPs are redirected to it. My RAMdisk starts with the system and in this case, update was quite big and 2nd part of the update was running after restart, so probably before RAMdisk could start or RAMdisk was too small for this update. I've changed paths for my TEMPs in environment variables (variables TEMP and TMP) to an existing folder on the system drive and it was last thing before a succeeded update attempt.

Since I wasn't making update attempts in between those 4 last mentioned steps I can't say for sure what combination of them helped, but I have a vague memory I've had a quite similar issue few years ago and back then it was due to update being unable to get to TEMP locations due to changed paths - not having enough available space and might have been just the same now.

A tip for MS crew: if the update needs disk space, let it create a folder in Windows folder for its own and delete it after the update is done as last part of the installation, that would make the update independent of TEMPs paths that can be changed to a disk too small or unavailable during boot up.

If it doesn't help you, focus on the error code for solutions connected to the error code instead of solutions to problems connected with the update number. Update is new, most error codes are much older, so it's very likely there's more to find looking for error code.

Best regards,

miauek

Mark,

glad that it worked for you. It didn't for me and I suspect the explanation is not the difference in online vs offline installers but the installation history of our PCs prior to applying KB4592438. Before I saw your response, I posted the steps I took to resolve it. In that post, I forgot to mention the offline installer but did so in an earlier one. But everyone affected should give the offline installer a try in any case.

Regards,

Roland

I was in a boot loop in 630 so I did the

Download KB4592438 Offline Installer

option and it's all good now. 

Updated to 685

What version of Windows 10 did you have installed before making this update. Did you make the KB4586853 which passed in 19042.661?

This was my case and when I wanted to install the preview of the new cumulative update about a week ago, I had for the 1st time had an installation failure. After several attempts, I had decided to wait for last night's cumulative update KB4592438 to switch to 19042.685. And what I was afraid has happened again, this update failed with error 0x800f081f. After having tried all the panoply of repairs: all the commands DISM, SFC / Scannow ... the installation failed each time although I had never had an installation failure on my machine before. As I am careful, I always keep multiple full system backups with AOMEI and EASUS. So I had the idea of ​​restoring a backup of 19042.630, which therefore preceded 661. And there, immediately after the restore, the installation of the cumulative update KB4592438 went without a hitch. . So I only had a few updates of various software, released in the meantime, to return to a top system, in version 19042.685

So if you were in 661, it might be the same kind of problem and, provided you also have backups, you could go back to 630, before installing the new cumulative.

Here, I took the lead a little, but now it rolls, and for me, it was the 661, which gave me the discord.

Wishing it could serve you,

Good night.

661 was pulled, it's 662 now.

I could only get 631 to install, maybe I roll back to 630 and try 662?