L2TP VPN connection failing

Description

New Windows KB5009543, KB5009566 updates break L2TP VPN connections affecting Windows 10 and 11.

When attempting to connect to a VPN, an error is shown as below:

Image

Resolution

In order to fix this issue is necessary to run a command in the command prompt as administrator. 

  • Windows 10: wusa /uninstall /kb:5009543
  • Windows 11: wusa /uninstall /kb:5009566

After running the command restart the machine and try the L2TP VPN connection again.

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