How to Fix Error 789 for Windows 10
To resolve this error, there are some steps you need to take.
- Check the certificate – This is the easiest thing to do. All you have to do is make sure the correct certificate is used on both the server and the client side.
- Re-enable IPSec on your computer – This one is a bit more involved, but we will simplify it for you. Right click on the Windows icon in the lower left hand corner and select Run. When the prompt comes up, type in services.msc. From this point, look for IKE and AuthIP IPSec Keying Modules and under that heading, find the IPSec Policy Agent. Now, check the status. If it says started, click on it to restart. If the started option is disabled, enable it. Next, change the Startup Type from Manual to Automatic. Save your changes, and restart your VPN service.
- Reset the network adapter – Right click on the Windows icon in the lower left hand corner and select Device Manager. Find the Network adapter and right click on it to Uninstall. Now, restart your computer and that should certainly fix the issue.
And there you have the solutions to solving the Error 789 connection error when using L2TP. Of course, if these steps do not solve your issue, we suggest contacting the support of the VPN company you are using for further assistance.