Unable to Connect to the Microsoft Visual Studio Remote Debugging Monitor

Applies to: Visual Studio Visual Studio for Mac

This message may occur because the remote debugging monitor is not properly set up on the remote machine or the remote machine is inaccessible due to network problems or the presence of a firewall.

What is the detailed error message?

The Unable to Connect to the Microsoft Visual Studio Remote Debugging Monitor message is generic. Usually, a more specific message is included in the error string and that may help you identify the cause of the problem or search for a more exact fix. Here are a few of the more common error messages that are appended to the main error message:

• The debugger cannot connect to the remote computer. The debugger was unable to resolve the specified computer name
• Connection request was rejected by the remote debugger
• Connection with the remote endpoint was terminated
• Invalid access to memory location
• There is no server by the specified name running on the remote computer
• The requested name was valid, but no data of the requested type was found
• The Visual Studio Remote Debugger on the target computer cannot connect back to this computer
• Access denied
• A security package specific error occurred

The debugger cannot connect to the remote computer. The debugger was unable to resolve the specified computer name

Try these steps:

1. Make sure that you enter a valid computer name and port number in the Attach to Process dialog box or in the project properties (To set properties, see these steps). The computer name must be the following format:

   computername:port

   Note

   The port number must match the port number of the remote debugger, which must be running on the target machine.

2. If the computer name does not work, try the IP address and port number instead.

3. Make sure that the version of the remote debugger running on the target machine matches your version of Visual Studio. To get the correct version of the remote debugger, see Remote Debugging.

   Tip

   If you are attaching to the process and you connect successfully but don't see the process you want, select the Show processes from all users check box. This will show processes if you are connected under a different user account.

4. If these steps do not resolve this error, see The remote machine is not reachable.

Connection request was rejected by the remote debugger

In the Attach to Process dialog box or in the project properties, make sure that the remote computer name and the port number matches the name and port number shown in the remote debugger window. If incorrect, fix and try again.

If these values are correct and the message mentions Windows Authentication mode, check that the remote debugger is in the correct authentication mode (Tools > Options).

Connection with the remote endpoint was terminated

If you are debugging an Azure App Service app, try using the Attach Debugger command from Cloud Explorer or Server Explorer instead of Attach to Process.

If you are using Attach to Process to debug:

• In the Attach to Process dialog box or in the project properties, make sure that the remote computer name and the port number matches the name and port number shown in the remote debugger window. If incorrect, fix and try again.

• If you are trying to connect using a host name, try an IP address instead.

• Check the application log on the server (Event Viewer on Windows) for more detailed information to help resolve the issue.

• Otherwise, try restarting Visual Studio with Administrator privileges, and then try again.

Invalid access to memory location

An internal error occurred. Restart Visual Studio and try again.

There is no server by the specified name running on the remote computer

Visual Studio could not connect to the remote debugger. This message may occur for several reasons:

• The remote debugger may be running under a different user account. See these steps

• The port is blocked on the firewall. Make sure the firewall is not blocking your request, especially if you are using a third-party firewall.

• The remote debugger version does not match Visual Studio. To get the correct version of the remote debugger, see Remote Debugging.

The requested name was valid, but no data of the requested type was found

The remote computer exists, but Visual Studio could not connect to the remote debugger. This message may occur for several reasons:

• A DNS issue is preventing the connection. See these steps.

• The remote debugger may be running under a different user account. Follow these steps.

• The port is blocked on the firewall. Make sure the firewall is not blocking your request, especially if you are using a third-party firewall.

• The remote debugger version does not match Visual Studio. To get the correct version of the remote debugger, see Remote Debugging.

The Visual Studio Remote Debugger on the target computer cannot connect back to this computer

The remote debugger may be running under a different user account. In the remote debugger, open Tools > Permissions to add the user to the remote debugger's permissions. For more information, see The remote debugger is running under a different user account.

If the error message also mentions a firewall, the firewall on the local machine may be preventing communication from the remote computer back to Visual Studio. See these steps.

Access denied

You may see this error if you try to debug on a 64-bit remote computer from a 32-bit computer (not supported).

A security package specific error occurred

This may be a legacy issue specific to Windows XP and Windows 7. See this information.

Causes and recommendations

The remote machine is not reachable

If you cannot connect using the remote computer name, try using the IP address instead. You can use ipconfig in a command line on the remote computer to get the IPv4 address. If you are using a HOSTS file, verify that it is configured correctly.

If that fails, verify that the remote computer is accessible on the network (ping the remote machine). Remote debugging over the Internet is not supported, except in some Microsoft Azure scenarios.

The server name is incorrect or third-party software is interfering with the remote debugger

In Visual Studio, look at the project properties and make sure the server name is correct. See topics for C# and Visual Basic and C++. For ASP.NET, open Properties / Web / Servers or Properties / Debug depending on your project type.

If the server name is correct, your anti-virus software or a third-party firewall may be blocking the remote debugger. When debugging locally, this can happen because Visual Studio is a 32-bit application, so it uses the 64-bit version of the remote debugger to debug 64-bit applications. The 32-bit and 64-bit processes communicate using the local network within the local computer. No network traffic leaves the computer, but it is possible that third party security software may block the communication.

The remote debugger is running under a different user account

The remote debugger will, by default, only accept connections from the user who launched the remote debugger and members of the Administrators group. Additional users must be explicitly granted permissions.

You can solve this in one of the following ways:

• Add the Visual Studio user to the remote debugger's permissions (in the remote debugger window, choose Tools > Permissions).

• On the remote computer, restart the remote debugger under the same user account and password that you are using on the Visual Studio computer.

  Note

  If you are running the remote debugger on a remote server, right-click the Remote Debugger app and choose Run as administrator (Or, you can run the remote debugger as a service). If you are not running it on a remote server, just start it normally.

• You can start the remote debugger from the command line with the /allow <username> parameter: msvsmon /allow <username@computer>.

• Alternatively, you can allow any user to do remote debugging. In the remote debugger window, go to the Tools > Options dialog. When you select No Authentication, you can then check Allow any user to debug. However, you should try this option only if the other options fail, or if you are on a private network.

The firewall on the remote machine doesn't allow incoming connections to the remote debugger

The firewall on the Visual Studio machine and the firewall on the remote machine must be configured to allow communication between Visual Studio and the remote debugger. For information about the ports the remote debugger is using, see Remote Debugger Port Assignments. For information about configuring the Windows firewall, see Configure the Windows Firewall for Remote Debugging.

The version of the remote debugger doesn't match the version of Visual Studio

The version of Visual Studio that you are running locally needs to match the version of the remote debugging monitor that is running on the remote machine. To fix this, download and install the matching version of the remote debugging monitor. To get the correct version of the remote debugger, see Remote Debugging.

The local and remote machines have different authentication modes

The local and remote machines need to use the same authentication mode. To fix this, make sure that both machines are using the same authentication mode. You can change the authentication mode. In the remote debugger window, go to the Tools > Options dialog box.

For more information about authentication modes, see Windows Authentication Overview.

Anti-virus software is blocking the connections

Windows anti-virus software allows remote debugger connections, but some third-party anti-virus software may block them. Check the documentation for your anti-virus software to find out how to allow these connections.

Network security policy is blocking communication between the remote machine and Visual Studio

Review your network security to make sure that it is not blocking communication. For more information about Windows network security policy, see Security policy settings.

The network is too busy to support remote debugging

You may need to do remote debugging at a different time, or reschedule work on the network for a different time.

More help

To get more remote debugger help, open the remote debugger's Help page (Help > Usage in the remote debugger).

See also

• Remote Debugging