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

Carlo Mendoza 151

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?

Carlo Mendoza 151 Reputation points

2022-01-12T07:26:34.27+00:00

It looks like others are experiencing this issue: https://techcommunity.microsoft.com/t5/report-an-issue/windows-11-update-kb5009566-inhibits-vpn-connection/m-p/3057844
Thunder Solutions 51 Reputation points

2022-01-12T14:54:27.927+00:00

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....
Anderson Wavrik 21 Reputation points

2022-01-12T23:26:40.79+00:00

This is happening not only in Windows 11 but in Windows 10 too. How can i fix this or downgrade?
Birdman .....Annoyed 6 Reputation points

2022-01-13T00:30:28.05+00:00

How did you uninstall 5009543 ??

I try and it tells me its a required update and cannot be uninstalled.
remoteitguy44 36 Reputation points

2022-01-13T01:38:55.127+00:00

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.
Robert Pearman 36 Reputation points

2022-01-13T11:57:14.127+00:00

Just to say I had to remove KB5009543 & 2 other updates before the VPN would connect.
Becca Rose 1 Reputation point

2022-01-13T13:19:08.12+00:00

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....
Ketan Tejani 1 Reputation point

2022-01-13T13:26:03.737+00:00

Thanks for this post - I got same isssue and your post saved me from agonizing pain I would have gone through.
Howard Beattie 1 Reputation point

2022-01-13T15:34:11.977+00:00

Robert,

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

Cheers!
H
Gabor Szucs 6 Reputation points

2022-01-13T16:34:28.83+00:00

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!
Guillermo Delgadillo 1 Reputation point

2022-01-13T17:26:05.727+00:00

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
David B 1 Reputation point

2022-01-14T09:18:24.773+00:00

Solved VPN Issue. THANK YOU!
Igor Valsichi 1 Reputation point

2022-01-14T11:24:57.143+00:00

it seems to affect AZURE SSTP Vpns as AZURE AD uses do authenticate users
Igor Valsichi 1 Reputation point

2022-01-14T11:28:09.297+00:00

Thank you MS!

MS is giving us an opportunity to make money (lol)
Giovanni 1 Reputation point

2022-01-14T11:37:50.387+00:00

Also experiencing this problem. When can we typically expect a fix for this from Microsoft? Thanks
remoteitguy44 36 Reputation points

2022-01-14T12:02:37.217+00:00

This KB article has been replaced by a useless FAQ that says your only choice is to suspend updates for 7 days.
Debbie Balser 1 Reputation point

2022-01-14T19:34:23.283+00:00

I had the same problem , had to to uninstal the update to get VPN working lost 2 days of work !!
Geeves 16 Reputation points

2022-01-16T21:54:11.663+00:00

Windows 10: wusa /uninstall /kb:5009543
Windows 11: wusa /uninstall /kb:5009566
IkhsanC 11 Reputation points

2022-01-17T03:23:04.49+00:00
TRY to use this

OPEN POWERSHELL (ADMINISTRATOR)

TYPE> WMIC QFE LIST BRIEF /FORMAT:TABLE

TYPE> WUSA /UNINSTALL /KB:(NUMBER)
IkhsanC 11 Reputation points

2022-01-17T03:24:03.9+00:00
TRY THIS:

OPEN POWERSHELL (ADMINISTRATOR)

TYPE> WMIC QFE LIST BRIEF /FORMAT:TABLE

TYPE> WUSA /UNINSTALL /KB:(NUMBER)
Er Mandhon 1 Reputation point

2022-01-17T04:38:09.07+00:00

trims dude, worked
Boye Madsen 1 Reputation point

2022-01-17T05:41:12.563+00:00

Hi

I g’et the same answer Update can’t be uninstalled. But thank you for the answer.
IT Saunders 6 Reputation points

2022-01-18T14:14:02.29+00:00

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
TZ 76 Reputation points

2022-01-18T16:21:31.443+00:00

not for W10
Marcus Hammer 1 Reputation point

2022-01-19T09:55:29.817+00:00

Removing 5009543 helped out for me. L2TP/IPSEC works again.

I have reported to Microsoft through Feedback hub and I think all that experience this should do the same to get MS's attention.

We have 30 computers at our company suffering from this!

Feedbackhub:
https://support.microsoft.com/en-us/windows/send-feedback-to-microsoft-with-the-feedback-hub-app-f59187f8-8739-22d6-ba93-f66612949332
Balazs 1 Reputation point

2022-01-21T08:32:47.673+00:00

Dear Everyone,
I use windows 10 and I experienced after installed windows10.0-kb5010793 patch not fully solved the problem…
I can connect to VPN from home network but if I use a mobil hotspot wifi then I can't connect to VPN and I get similar error message.
Is there problem anyone? Anyone know how to fix it? The uninstalling could't solve this problem.
Thank you in advance for your help.
Ethan 1 Reputation point

2022-02-01T19:29:17.483+00:00

I am setting up a new computer that we just purchased and having this same issue, so there isn't a previous update to roll back to. Is there another solution besides uninstalling KB5009566?
Wayne Schoeman 1 Reputation point

2022-02-02T15:15:09.583+00:00

Just change the type to pptp

34 answers

Markus Rüegg 6 Reputation points

2022-01-13T08:02:57.613+00:00

Same here with win10. deinstallation kb5009543 works fine and the problem is "solved"
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Jimmy Hytönen 1 Reputation point

2022-01-13T08:48:34.973+00:00

Same here with Win10, VPN L2TP suddenly stopped working.
Uninstalling kb5009543 fixed the issue.
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Sarah Gheith 1 Reputation point

2022-01-13T08:57:11.107+00:00

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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remoteitguy44 36 Reputation points

2022-01-13T08:58:45.473+00:00

Hopefully the fix is this easy.

kpackaging 6 Reputation points

2022-01-13T10:16:49.417+00:00

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

remoteitguy44 36 Reputation points

2022-01-13T10:51:02.147+00:00

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

Curt Riley 1 Reputation point

2022-01-14T15:55:10.077+00:00

@Sarah Gheith 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.
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remoteitguy44 36 Reputation points

2022-01-13T08:57:53.727+00:00

Note that windows update will keep reinstalling this update. So it will keep breaking over and over until MS fixes the L2TP issue or pulls it completely.
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Navin Kumar 6 Reputation points

2022-01-13T09:01:13.927+00:00

You can take help from - How to Fix VPN KB5009543 Problem in Windows 10

and remove the update from Windows 11 by following- How to Uninstall KB5009566 from Windows 11
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Can't connect to any VPN after today's Windows Updates / Windows 11

34 answers