“Changes to 64-bit applications are not allowed” w

Question

I'm using Visual Studio 2008, C#. I try to use edit-and-continue (edit the code while debugging), and get this exception:

"Changes to 64-bit applications are not allowed"

Why is that? Is there a workaround?

Answer 1

The edit-and-continue feature simply hasn't been implemented in x64 yet. I haven't heard any updates on when they plan to do it yet.

See also Why doesn't Edit and Continue work on the x64 CLR?

Answer 2

Unfortunately, Edit and Continue isn't supported on 64-bit. In fact, if you try to use Edit & Continue when debugging a 64-bit application, you get the following error message: "Changes to 64-bit applications are not allowed" Many users may not be aware that by default, when you create a C# or VB project in Visual Studio 2008, the "Platform" for the project is set to "Any CPU". This means that if you run your application on a 32-bit operating system, your application will run as a 32-bit process and similarly, if you run your application on a 64-bit operating system, the application will be 64-bit. The consequence of "Any CPU" is that when you try to debug your application on a 64-bit operating system, you won't be able to use the Edit and Continue feature.

However, there is a workaround. During development, you can set the Platform for your project to 32-bit which means that your application will run as a 32-bit process even on a 64-bit operating system. This is known as WOW64 or "Windows On Windows" which basically means that you can run a 32-bit application on a 64-bit operating system.

So, how do you set the Platform for your project to 32-bit? Well, you need to create a 32-bit platform using the Visual Studio Configuration Manager. Here is a short walkthrough.

First, open the "Configuration Manager" dialog from Build –> Configuration Manager. The Configuration Manager dialog is shown below.