What Does That VPN Error Code Mean?


If you are reading this, I assume you must have befall for the VPN error code which causes it impossible to connect. When you find the log file, you’ll notice error codes listed in there. You’ll want to know what those codes mean to get a solution. Manually setting up VPNs are even more plausible to proffer you with error codes because there’s no company program between you and the underlying system of the VPN connection to understand the meanings of those errors for you.

In this VPN error code guide, we describe the most commonly encountered VPN error codes. We also recommend fixes for the difficulties that these codes signify. (also see, Best VPN for PC 2018)

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VPN Error Code 0x800704C9

– No SSTP ports on the server

This error is quite prevalent and is simple to fix. You require having access to the Remote Access Server to fix this.

  • Head to the Routing and Remote Access control panel.
  • Open the entry for your server.
  • Hover the cursor over Ports and click on the right mouse button. Select the Properties from the context menu.
  • Click on the Name and select WAN Miniport (SSTP) then click on Configure.
  • Look at the number in the Maximum Ports field. By default, this should be 128. Expand the number that is shown.
  • Click on the OK in the Port Properties window to close it.

VPN Error Code 51

– Unable to communicate with the VPN subsystem

The Cisco VPN system generates this error code. It relates to the VPN client, which is the VPN client software running on your computer. The VPN software can’t get through to the basic network software on your computer to form a connection. This shows something has hampered. Close down the VPN and start network diagnostics. Launch the VPN up again and see if this has fixed the error.

VPN Error Code 0x80072746

– Connection closed by remote host

This problem relates to HTTPS authentication certificates. Either the VPN server can’t find the certificate, or there is some problem with it.

You can’t fix this error yourself. It’s an error that is the duty of the people who own and maintain the VPN server. If you’re on a subscription VPN service, all of the company’s other clients will also be locked out. The VPN’s professionals will already know about the issue.

VPN Error Code 412

– The remote peer is no longer responding

This is a Cisco VPN error code that appears from the VPN client software. This is very comparable to error 51. But, in this instance, the client application was signing with the VPN server but lost the connection. Close down the VPN app, run network diagnostics, make sure your internet connection is working fine, then turn the VPN on again.

VPN Error Code 633

– The modem (or other connecting devices) is already in use or is not configured properly

This problem arises when another program is already using the Transmission Control Protocol (TCP) port that the VPN connection needs. It could be that the other plan stalled, or fell over without completing the resource release procedures are necessary to make the TCP port available to other processes.

The solution to this problem is very similar to the steps for solving error 609. The diagnostics fix won’t be able to help you, but restarting the Remote Access Manager should clear all blocked ports. If a rogue process doesn’t die, restart your PC to clean out the dead wood.

VPN Error Code 645

– There was an internal authentication error

This error happens on older, out-of-date versions of Windows. You’re more prone to get error code 691 on later versions of the operating system. The error transpires when the VPN server disallows a connection because you inscribed an incorrect username and password.

VPN Error Code 691

– Access denied because username and password is invalid on the domain

This problem should be straightforward to fix. It appears when you enter the incorrect username or password. Be sure that Caps Lock is off because these credentials are case sensitive. Also, ensure that the username and password that the network administrator or the VPN service provided is correct by checking back with them to confirm. At this point, the administrator should also check that your account has been set up on the VPN server.

VPN Error Code 720

– A connection to the remote computer could not be made

This problem happens on Windows computers where you’ve manually set up a VPN definition. The possible reason for the error is that you gave in the wrong protocol in the VPN Type field. Try setting the type to Automatic and then retest the connection. If that doesn’t fix the problem, read through the VPN’s online documentation to get the right protocol for the server that you want to connect to. If all else fails, ask the VPN company’s help desk.

VPN Error Code 721

– The remote computer did not respond

This is a Windows error that appears due to a malfunction of the VPN client software operating on your computer to get through to the underlying networking software. Close the VPN, run network diagnostics, make sure your internet connection is working fine, then turn the VPN on again.

VPN Error Code 732

– Your computer and the remote computer could not agree on PPP control protocols

This Windows error could come either on your computer or on the VPN server. This is a problem that occurs when the user account doesn’t have the access rights to VPN sources. The issue could relate to the user account subscriptions on your computer, the access authorities to the network (if you’re connecting through a business or university network), or on the VPN server.

The most usual location for the source of this error, if you are a VPN user of a private subscription service, is on the VPN server. As such, you’ll require contacting the VPN’s help desk to fix this error.

VPN Error Code 734

– The PPP link control protocol was terminated

This is somewhat a variation on error code 732. It happens when a connection was built, but then denied for some reason associated with resource access rights. Talk to your VPN provider’s help desk to resolve this issue.

VPN Error Code 766

– A certificate could not be found

This error appears on connections with the Layer 2 Tunneling Protocol (L2TP) over Internet Protocol Security (IPSec). The connection needs the presence of an authentication certificate on the consumer and the VPN server. One of those certificates was not there for this connection, so creating an error. Your VPN provider should be able to fix this error.

VPN Error Code 789

– The security layer encountered a processing error during initial negotiations with the remote computer

This is a general error relating IPSec connection negotiations for L2TP. This is another error code that could refer to the lack of security certificates or inconsistencies between the identity of either the user or the server and the details given on their respective certificates. If the system is employing Pre Shared Keys (PSK) assure that both the client and the server have the same key.

VPN Error Code 809

– The network connection between your computer and the VPN server could not be authenticated because the remote server is not responding

This is a comparable problem with error 806. It’s caused by a firewall or router along the journey blocking access to TCP 1723. Contact your ISP to solve this problem.

VPN Error Code 868

– The remote connection failed to build because the name of the remote access server did not resolve

If you’re lucky, this error was caused because you are written the name of the server wrong while setting up the VPN. Reach out the help desk and verify the name of the server that you should be connecting to. Also, demand them to give you the server’s IP address. This difficulty could have been caused by an incorrect entry in the Domain Name System (DNS), which interprets hostnames into IP addresses. Changing the server name with the actual IP address is the handiest way to solve this problem.

Check the server name in the VPN connection configuration. If you had the name correct, replace the name of the server with the IP address, make sure you’ve written your username and password correctly and start the VPN connection again.

VPN Error Code 13801

– IKE authentication credentials are unacceptable

This Internet Key Exchange version 2 (IKEv2) error is all about issues with the server authentication certificate. As you have no authority over the server, there is the minimum you can do to fix this error. You will have to reach the VPN provider’s help desk and get them to fix the error.

Conclusion -What Does That VPN Error Code Mean?

Dealing with a string of errors when you try to connect to a VPN can be incredibly frustrating. Low-quality VPNs have poor customer support, and it can take days to get a reply. If a VPN business has a slow help desk, their support workers probably won’t be very experienced either, so the first response to your support ticket may be an obtuse response that completely misses the point. Cheap support teams love to flag issues as resolved as quickly as possible. They frequently misunderstand the problem intentionally so they can get you off their queue and keep their response ratings up.


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