November 2019 updates caused Windows Server 2012 reboot loop


Some laggards that still have some Windows Server 2012 virtual machines running got a bit of a nasty surprise last weekend. A number of them went into a boot loop. Apparently the November 2019 updates caused Windows Server 2012 reboot loop. Well, we have dealt with update issues before like here in Quick Fix Publish : VM won’t boot after October 2017 Updates for Windows Server 2016 and Windows 10 (KB4041691). No need to panic.


Not all Windows Server 2012 virtual machines were affected. We did not see any issues with Windows Server 2012 R2, 2016 or 2019. Well the symptom is a reboot loop and below I have a sequence of what it looked like visually.

November 2019 updates caused Windows Server 2012 reboot loop
Looking good so far …
OK, stage 2 of 4 … stlil seems OK.
November 2019 updates caused Windows Server 2012 reboot loop
Could still be OK … but no, its starts again in an endless loop.

So what caused this Windows Server 2012 reboot loop?


We turned of the virtual machines on which the November 2019 updates caused Windows Server 2012 reboot loop. We started them up again in “Safe mode” which completed successfully. Finally, we then did a normal reboot and that completed as well. All updates had been applied bar one. That was the 2019-11 Servicing Stack Update for Windows Server 2012 (KB4523208).

We manually installed it via Windows update and that succeeded.

When reading the information about this update its states it need to be installed exclusively.

Maybe that was the root cause. It got deployed via WSUS with the other updates for November 2019.

Anyway, all is well now. I remind you that we have at least 2 ways of restoring those virtual machines. In case we had not been able to fix them. Have known good backups and a way to restore them people.


We fixed the issue and patched those servers completely. So all is well now. Except for the fact that they now , once more, have been urged to get of this operating system asap. You don’t go more than N-2 behind. It incurs operational overhead and risks. They did not test updates against this old server VM and got bitten. Technology debt without a plan is never worth it.

11 thoughts on “November 2019 updates caused Windows Server 2012 reboot loop

  1. You can try this too for revert current update state (Worked for me)
    Boot on ISO of WS2012
    Command prompt:
    mkdir c:\scratch
    dism /image:c:\ /scratchdir:c:\scratch /cleanup-image /revertpendingactions
    Replace “C:” of your windows install folder letter (Diskpart to identify)
    Sorry for my bad english

  2. I had this happen with two physical Windows Server 2012 systems. Both didn’t have a virtual console.

    I had a support case open last year (while 2012 was still in mainstream support) requesting a bug fix be released for a bug that had been fixed only in 2012 R2. The support rep told me that Server 2012 was out of support and to upgrade to R2. I referenced the product lifecycle page that shows both 2012 and 2012 R2 have the exact same support dates. Then they showed me an email from their Microsoft contact indicating that they had no intention of releasing the bug fix. Regardless of what the lifecycle page indicates, Microsoft has no interest in properly supporting Server 2012.

    • While I would agree it needs to be phased out I do expect them to support it when it is still in the supported lifecycle phase. Not just a problem for older OS versions. There are not enough resources going to Windows Server on the whole.

  3. The experience has me concerned about newer release of Windows Server. What if the team has the same attitude about Server 2016 now that 2019 is out? There are comments in the Veeam forums indicating that Microsoft was considering not back-porting the ReFS performance fixes.

  4. I’ve seen the reboot loop happen this month where 2019-11 Servicing Stack Update for Windows Server 2012 (KB4523208) wasn’t involved so I don’t think it is the root cause of the problem.

  5. hi there,

    I have the same problem here, already trying all steps above but still fail to boot.

    can you please help?


Leave a Reply

Your email address will not be published. Required fields are marked *

* Checkbox GDPR is required


I agree

This site uses Akismet to reduce spam. Learn how your comment data is processed.