Error: A 64-bit debugger operation is taking longer than expected

You might see one of the following errors:

In these scenarios, Visual Studio sent a request to msvsmon.exe, and it's taken a long time for the result of that request to come back.

The most common causes for this error are:

You have networking security software installed on your computer that has caused the networking stack to be unreliable, and it's dropped packets going over localhost. Try disabling all network security software and see whether this resolves it. If so, report to your network security software vendor that the software is interfering with localhost traffic. This shouldn't occur with Visual Studio 2019 and later, because those versions don't use sockets for this communication.
You're running into an issue where Visual Studio becomes unresponsive, or other performance problem. If the problem happens regularly, you can collect dumps of Visual Studio (devenv.exe) and the worker process (msvsmon.exe) and send them to Microsoft. For information about reporting a problem, see How to Report a Problem with Visual Studio.

If you're using a version of Visual Studio prior to Visual Studio 2022, you may be trying to debug a 64-bit application while running in the 32-bit Visual Studio process. To resolve, follow instructions to debug a 64-bit application.

In Visual Studio 2019 and earlier versions, you may be trying to debug a 64-bit application while running in the 32-bit Visual Studio process. To resolve, follow instructions in this article to debug a 64-bit application.

Debug a 64-bit Application

You can debug a 64-bit application that is running on the local computer or on a remote computer.

To debug a 64-bit application that is running on a remote computer, see Remote Debugging.
To debug 64-bit applications locally, Visual Studio uses a 64-bit worker process (msvsmon.exe) to perform the low-level operations that can't be done inside of the 32-bit Visual Studio process.

Mixed-mode debugging isn't supported for 64-bit processes that use .NET Framework version 3.5 or earlier.

To try debugging a 64-bit application locally:

Create a Visual Studio solution, for example a C# console application.
Set the configuration to 64-bit using the Configuration Manager. For more information, see How to: Configure Projects to Target Platforms.
At this point the 64-bit version of the remote debugger (msvsmon.exe) starts. It runs as long as the solution with the 64-bit configuration is open.
Start debugging. You should have the same experience as with a 32-bit configuration. If you still get the same error, see the beginning of this article for other suggestions.