789 is classically bad PSK, but it can also pop up when you’ve got a bad credential OR when Windows has changed the password protocol on you. If Windows 10, check out the scripts in my signature. Regardless of version, set Encryption to “optional”: Windows doesn’t support PAP with ‘required’ encryption.
When I plan to connect to my workplace using a virtual private network connection, I get error 789: The L2TP connection attempt was corrupted because the security layer encountered a processing error during initial negotiation with the remote computer. I am starting with lp2/ipsec.
If Product: uses Meraki authentication, make sure the user is normally authorized to run the VPN. Solution. If you choose to use Active Directory authentication with the VPN client, make sure the server screen offers a valid certificate for TLS.
When using Meraki Managed Authentication, use email addresses for many VPN accounts/usernames. Open the Start menu > Controller. On the flexible solar panel, click Grid Connections. In the “Network Tasks” section, click “Create a new real connection”. In each new window of the connection wizard, select Go to the current network connection at my workplace.
The following procedure will fix this error: 789, when configuring L2TP on ipsec in Windows 10. “Error: 789, L2TP connection retry failed because the security layer encountered a calculation error during remote negotiation initialization”, 1 Open “Administration Tools” from Control Panel.
Is there an error code for VPN error 789?
Quite often, Internet users encounter various problems when trying to use this secure connection, and no matter what operating system you are using, there is a high chance of multiple VPN error discount codes appearing. Today, the detection error might be VPN error 789.
How do I fix Error 800 789 L2TP and setup VPN in Windows 7?
Fix: Error 800 Windows 7 (L2TP client over IP Sec cannot connect)
- In Windows 7, go to VPN connection properties and click “Security”.
- Select L2TP/IPSec as VPN type and click “Advanced”.
< li>Select Use pre-sharing to authenticate the key and see OK.

Ermias is a tech writer with a passion for helping people solve Windows problems. He loves to write and share his knowledge with others in the hope that they can benefit from it. He’s been writing about technology and software since he was in college, and has been an avid Microsoft fan ever since he first used Windows 95.