Visual Studio 2022 and WinForms 32-bit .NET Framework components
Visual Studio 2022 is the first Visual Studio that runs as a 64-bit application. We received lots of requests to make this change and now you can open, edit, run, and debug the biggest and most complex solutions without running out of memory. This switch required fundamental architectural changes and there were some scenarios related to .NET Framework 32-bit components that we could not make work in Windows Forms designer.

In order to support .NET Core 3.1 and above we had to create an out of process designer. For .NET Framework, the designer remained in-process. The reason for that decision was to minimize breaking changes for 3-rd party controls that interact with Visual Studio. Since Visual Studio is now 64-bit, the .NET Framework-based designer now also runs in 64-bit, which means 32-bit code cannot be loaded at design time any longer. At the same time, to load controls for .NET Core, we created a new designer that runs out of process. Since that process can run as either a 32-bit or 64-bit process, it can be used with 32-bit controls . . So, for .NET 6, .NET 5, and .NET Core applications you have full designer support . But if you have a .NET Framework application that is referencing a 32-bit component, this component cannot be loaded in Visual Studio 2022 Windows Forms designer, and you will see a white error screen instead. This will not affect your end users, as your application will run just fine, it only affects the designer experience inside of Visual Studio.

In the future, we plan to add support for .NET Framework projects to the out of process designer. Once that support is available, it will be possible to load forms that have 32-bit specific dependencies in the designer.

Meanwhile there are a few ways to make your Forms show in the designer:

You can simply keep using Visual Studio 2019 for forms that have references to 32-bit components until we add support for .NET Framework projects to the out of process designer.
If you are an author of the component you are using, rebuild it for ‘x64’ for native components or ‘Any CPU’ for managed code. For managed code, the procedure should be very straight forward.
If a 32-bit component cannot be rebuilt, you can create a “design” configuration of the project, which targets 64-bits and where the 32-bit component is replaced with a 64-bit placeholder. This particular component will not be available at design time but the rest of the UI will be.
If you are using a third-party component, reach out to the author and ask them to provide an ‘x64’ or ‘Any CPU’-version of it.
For some cases, such as Visual Basic 6, producing 64-bit is not an option because they are legacy controls that don’t have an implementation on 64-bit CPU. We would suggest finding a .NET substitute for the component that provides similar functionality.