How To Fix VPN Error 789
The L2TP connection prompts “Error 789: The L2TP connection attempt failed because the security layer encountered a processing error while initializing the negotiation with the remote computer.” If it happens accidentally, it can be solved by replacing the line or restarting the computer. If this error is frequently prompted, you can try the following solutions.
1. The Win+R key combination opens the “Run” window (Win is the Microsoft icon key on the keyboard), enter regedit and click “OK” to open the registry editor.
2. Click to expand HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\RasMan\Parameters
3. Click “Edit” in the menu bar to create a new “DWORD(32) value”, fill in ProhibitIpSec for the name, write 1 for the value data, and select hexadecimal for the base, as shown in the figure below.
4. Click OK to save and exit, restart the computer to take effect, and then try VPN L2TP connection again.
If you find the above steps cumbersome, you can make a registry patch to import, the method is as follows:
Open the Notepad program, copy the following content into it, save it as a l2tp-789-error.reg file (note that the file suffix is reg), and then double-click to run the import.
