Windows 10 native VPN Client: I am unable to connect to VPN servers

Lars Ole Ottesen 1 Reputation point

Suddenly I cannot connect to the two VPN services I have used for a long time. I get this error 'The L2TP connection attemt failed because the security layer encounted a processing error ...'

I looks very much like the error many of us had in the spring. The cure at that time was to remove the KB5009543 update, which helped. The two VPN servers are a Cisco Meraki and a Zyxel.

Does anyone knows how to solve this new incident.

Windows 10 Network
Windows 10 Network
Windows 10: A Microsoft operating system that runs on personal computers and tablets.Network: A group of devices that communicate either wirelessly or via a physical connection.
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  1. Limitless Technology 44,081 Reputation points


    If this has happened recently, I suggest that it may be a recent security patch again. Try removing the most recent security patches via appwiz.cpl to see if the issue is resolved.

    I hope this answers your question.


    --If the reply is helpful, please Upvote and Accept as answer--

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  2. Lars Ole Ottesen 1 Reputation point

    It suddenly started working again. I think it has been the internet provider blocked some ports, when they made an update to the firmware modem.

    It works now, thanks.

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