Troubleshooting VPN Error 691 in Windows PC

A virtual private network (VPN) is an important online tool that can help you improve your online privacy and security. While VPN tools are great, they have several issues that can lead to VPN connection loss and error messages.

Several users have reported that the connection failed with a VPN 691 error. This can be an obstacle if you want to use a VPN. Fortunately, there are several ways to solve this problem on your own.

What causes the VPN 691 error message?

An error is a connection error that occurs when the connection you have is not dial-up. A VPN 691 error occurs when the client or server machine settings are not set correctly, which means that the connection cannot be verified. Usually, the 691 error is caused by an incorrect username or password. In other cases, it can occur if you’re using a public VPN and trying to connect to it with an unauthorized domain, or if the required security protocols don’t match.

Users report that VPN 691 error occurs when there are problems with network protocol settings, remote access permissions, firewall permissions, connectivity issues, etc. The most common causes can be divided into three categories:

  • Incorrect username and password
  • Incorrect connection security settings
  • Problems with network settings

How to resolve VPN 691 error?

Removing and adding a VPN connection

  1. Press the Windows + I keys to open the Settings app.
  2. When the Settings app is open, go to the Network and Internet section.
  3. Now go to the VPN tab.
  4. Under the VPN section, you should see all the available VPN connections.
  5. Select the connection you want to delete and click the Delete button.
  6. Now you need to add a new VPN connection. To do this, click the Add VPN Connection button.
  7. Then enter the information you need to set up the VPN connection.

Update the network driver

  1. Go to Search, type devicemngr, and open Device Manager.
  2. Expand Network Adapters and find your router.
  3. Right-click on your router and go to Update Driver.
  4. Follow the instructions on the screen and complete the driver installation.
  5. Restart your computer.

Using Microsoft CHAP version 2

  1. Press the Windows + X key to open the Win + X menu.
  2. Select Network Connections from the menu.
  3. When the Network Connections window opens, find your VPN connection, right-click it, and choose Properties from the menu.
  4. Click the Security tab.
  5. Select Allow these protocols and enable Microsoft CHAP version 2 (MS-CHAP v2).
  6. Click OK to save your changes.

Check the security settings of your connection

  1. Open the Network Connections window.
  2. Find your connection, right-click it and click Properties.
  3. Click the Security tab and make sure that Typical is selected.
  4. In the Verify My Identity section, make sure that Allow unsecured passwords is selected as follows.
  5. Click the Options tab and make sure that the Include Windows login domain is not selected.
  6. Click OK to save your changes.

Frequently Asked Questions

  1. Set up private Internet access.
  2. Use Microsoft CHAP version 2.
  3. Uncheck the Enable Windows connection domain option.
  4. Change the LANMAN settings.
  5. Check that the username and password are correct.
  6. Update your network drivers.
  7. Check the security settings of your connection.

If your VPN software isn't working properly, there are a few things you can do: check your network settings, change your server, make sure the right ports are open, disable your firewall, and reinstall your VPN software.

  1. Make sure your Windows 11/10 is updated to the latest version. Some updates fix known VPN problems, which helps right away.
  2. Install the latest versions of network drivers or try older drivers to see if that solves the problem.

  1. Check your Internet connection.
  2. Check the connection data.
  3. Change the connection to the VPN server.
  4. Restart the VPN software or browser plug-in.
  5. Check if your VPN software is updated.
  6. Check if your browser is up to date.
  7. Reinstall the latest version of the VPN software.