question

carlomendoza avatar image
27 Votes"
carlomendoza asked ChristopherSzabo-2832 commented

Can't connect to any VPN after today's Windows Updates / Windows 11

I'm now getting this error trying to connect to VPN on Windows 11: The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer.

I've noticed this on 2 Windows 11 laptops (one personal and another for work). Both have been updated today and no longer able to connect to a couple VPNs.

2022-01 Cumulative Update for Windows 11 for x64-based Systems (KB5009566)

Anyone else? Anyone know how to fix it other than uninstalling the update?

windows-11
· 28
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So today I was near to shot my head, same problem with windows 10 uninstall kb5009543 and everything will work again. First I uninstall kb5008876 but no effect, then....


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9 Votes 9 ·
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remoteitguy44-8438 avatar image remoteitguy44-8438 ThunderSolutions-2910 ·

Thanks for the post. Same problem with Windows 10. I removed kb5009543 and my VPNs started to work again. It cost me a very important meeting as I was fighting with my laptop trying to get things functioning. The fact that Microsoft still pushes out updates like this after well over 20 years of patch screw-ups like this is not surprising.

5 Votes 5 ·

Thank you! This worked. Also for anyone wondering how to uninstall the windows update, you can follow this guide if you don't want to use powershell: https://www.tomsguide.com/how-to/how-to-uninstall-a-windows-10-update

0 Votes 0 ·
BirdmanAnnoyed-7785 avatar image BirdmanAnnoyed-7785 ThunderSolutions-2910 ·

How did you uninstall 5009543 ??


I try and it tells me its a required update and cannot be uninstalled.

1 Vote 1 ·
IkhsanC-2991 avatar image IkhsanC-2991 BirdmanAnnoyed-7785 ·

TRY THIS:
1. OPEN POWERSHELL (ADMINISTRATOR)
2. TYPE> WMIC QFE LIST BRIEF /FORMAT:TABLE
3. TYPE> WUSA /UNINSTALL /KB:(NUMBER)

1 Vote 1 ·
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IkhsanC-2991 avatar image IkhsanC-2991 BirdmanAnnoyed-7785 ·

TRY to use this
1. OPEN POWERSHELL (ADMINISTRATOR)
2. TYPE> WMIC QFE LIST BRIEF /FORMAT:TABLE
3. TYPE> WUSA /UNINSTALL /KB:(NUMBER)

0 Votes 0 ·
beccodes avatar image beccodes ThunderSolutions-2910 ·

This worked for me, removed kb5009543 on windows 10 and rebooted and my VPN reconnected immediately. Pausing updates for a few weeks so Microsoft can repair this update....

0 Votes 0 ·
KetanTejani-4229 avatar image KetanTejani-4229 ThunderSolutions-2910 ·

Thanks for this post - I got same isssue and your post saved me from agonizing pain I would have gone through.

0 Votes 0 ·

THANK YOU!!!!
this finally worked and the VPN is connecting again, had to go through lots of hours researching just to find Microsoft singing Ups I did it again, GRRRR

0 Votes 0 ·

Just to say I had to remove KB5009543 & 2 other updates before the VPN would connect.

2 Votes 2 ·

Robert,

What were the other 2 updates you uninstalled and are you running Windows 10 or 11.

Cheers!
H

0 Votes 0 ·

This is happening not only in Windows 11 but in Windows 10 too. How can i fix this or downgrade?

0 Votes 0 ·

After a day of figuring out why the L2TP/IPSec PSK connection not working (till yesterday morning), I found the same: I had to remove KB5009543!
Unfortunatelly I can't hide this upgrade (or any other) from the update list like I did in Win7 for example.

BUT!I found this:
https://tweaks.com/windows/67132/how-to-block-specific-driver-or-patch-updates-in-windows-10/

It works!

0 Votes 0 ·

This KB article has been replaced by a useless FAQ that says your only choice is to suspend updates for 7 days.

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JuliusHardt-2535 avatar image
7 Votes"
JuliusHardt-2535 answered

I experienced this same issue with exactly the same error message on all of my Win 11 machines, too (using an L2TP VPN with a pre-shared key and PAP). After uninstalling KB5009566, I could connect successfully again, so it is likely that the issue is indeed related to the update. (Of course, uninstalling security updates is not a good idea, this was just for testing purposes.)

If you want to record the problem or upvote it, here is a Feedback Hub item you may link to: https://aka.ms/AAffr20


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Reza-Ameri avatar image
1 Vote"
Reza-Ameri answered Reza-Ameri commented

Thank you for reporting this issue and like the discussion in this community, I believe this is a bug, so make sure open start and search for feedback and open the Feedback Hub app and report this issue.
As workaround, you may uninstall the update and restart your PC.

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So how do I uninstall this for 150 users?

Windows 10 will not allow for uninstall of 5009543. It is apparently necessary for your system according to the MS overlords

0 Votes 0 ·
Reza-Ameri avatar image Reza-Ameri BirdmanAnnoyed-7785 ·

It depends on your organization's infrastructure.
In case you are using WSUS , it could be done easily using its interface.
In other case, you might deploy PowerShell scripts.

0 Votes 0 ·
Uriel-3713 avatar image
0 Votes"
Uriel-3713 answered PascalSeiler-5592 commented

Yes, uninstalling last security update make the trick

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I receive an error when i try to uninstall the update

0 Votes 0 ·
BirdmanAnnoyed-7785 avatar image
0 Votes"
BirdmanAnnoyed-7785 answered

Good old Microsoft... its unlike them to break 80% of the computers on the planet with an update...

Windows 10 - Cannot uninstall the update - its "required"...

So what now?

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AndersonWavrik-2977 avatar image
0 Votes"
AndersonWavrik-2977 answered

I managed to uninstall the last update on Windows 10, it is the last from Security Update and works.

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remoteitguy44-8438 avatar image
0 Votes"
remoteitguy44-8438 answered

FYI to uninstall this worked for me.. open up a command line and do this: wusa /uninstall /kb:5009543

If you have domain group policy in place it may block that. Fortunately this is a non domain machine.

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Docs-4663 avatar image
0 Votes"
Docs-4663 answered Docs-4663 edited

If you want to remove the LCU (Latest Cumulative Update):


To remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument.
You can find the package name by using this command: DISM /online /get-packages.


Running Windows Update Standalone Installer (wusa.exe) with the /uninstall switch on the combined package will not work because the combined package contains the SSU.
You cannot remove the SSU from the system after installation.



https://www.elevenforum.com/t/kb5009566-cumulative-update-for-windows-11-build-22000-434-jan-11.3932/



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MarkusRueegg avatar image
0 Votes"
MarkusRueegg answered

Same here with win10. deinstallation kb5009543 works fine and the problem is "solved"

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JimmyHytnen-5769 avatar image
0 Votes"
JimmyHytnen-5769 answered

Same here with Win10, VPN L2TP suddenly stopped working.
Uninstalling kb5009543 fixed the issue.

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SarahGheith-7549 avatar image
0 Votes"
SarahGheith-7549 answered CurtRiley-0751 commented

There's probably no need to uninstall the security update. I ran into this issue today.
In my case, I just had to go through the security settings for the vpn-connection.
The data Encryption was changed from 'Require encryption' to 'Optional encryption' :)

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Hopefully the fix is this easy.

0 Votes 0 ·

Unfortunately, this didn't worked for me....

0 Votes 0 ·

Just tested this. This is not the solution. Optional was already set.

0 Votes 0 ·

@SarahGheith-7549 I am not sure if you are saying that you found your settings changed from 'Require encryption' to 'Optional encryption', and you had to change it back, or if you changed it from 'Optional encryption' to 'Require encryption'. But mine was set to 'Optional encryption' and failing to connect. I changed it, one setting at a time, to each setting, and tested again and again. No matter which setting I used, none would allow me to connect to my VPN. The only solution that worked, was to uninstall the update and reboot. Unfortnately, MS in the infinite ignorance or total lack of giving a crap, just pushed the update out again, unless I set my network to metered.

0 Votes 0 ·