Designer crashes when running Visual Studio 17.7.0 as a DpiUnaware process

[rafcolson]

Environment

Version 17.7.0

.NET version

.NET 6.0

Did this work in a previous version of Visual Studio and/or previous .NET release?

Same issue as described in #7609. Reemerged after the last update released on August 8th, 2023 (Visual Studio 2022 version 17.7).

Issue description

In order to run VS in DpiUnaware mode, I use this registry setting:

[HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers] "C:\\Program Files\\Microsoft Visual Studio\\2022\\Community\\Common7\\IDE\\devenv.exe"="DPIUNAWARE"

Having added the key and value to the registry, VS fails to launch the designer when viewing the form's designer in my solution, throwing this error:

[15:35:39.852848] fail: [MyProject]: Failed to launch design tools server process process
                        System.InvalidOperationException: Failed to set process DPI mode value to: DpiUnaware.
                           at Microsoft.WinForms.Utilities.Desktop.DpiHelper.SetDesignerProcessDpiAwareness(DpiAwarenessContext dpiContext)
                           at Microsoft.DotNet.DesignTools.Server.Program.<>c__DisplayClass2_0.<<Main>b__1>d.MoveNext()

                        For information on how to troubleshoot the designer refer to the guide at https://aka.ms/winforms/designer/troubleshooting.

Steps to reproduce

• add key and value to the registry
• open solution
• view the form's designer (Right-click on the form and choose "View Designer")

Diagnostics

No response

[Olina-Zhang]

Reproduce it in Version 17.7.0 and the latest VS build from main branch. It doesn't reproduce in Version 17.6.5.

[Shyam-Gupta]

@rafcolson Fix for this issue has been implemented and it should be available in next 17.8 Preview release.

I would also like to mention that starting with 17.8 Preview 1, a new project property ForceDesignerDpiUnaware has been introduced which will help launch WinForms out-of-process designer in DPIUnaware mode. More details about this property are available here. Thanks.

[rafcolson]

@Shyam-Gupta That's great! Thanks for that fix. Also looking forward to using the ForceDesignerDpiUnaware option. It surely will make it a lot less awkward to work on projects in DpiUnaware mode.

[MandiMan]

Verified this issue in the latest VS build: 17.8.0 Preview 2.0 [34017.374.main], it was fixed. When using registry key as following screenshot to set VS as DpiUnaware mode, the form designer loads successfully.