.NET 9 appears to break Windows API clipboard functionality · Issue #12184 · dotnet/winforms
github.com
Description Using the Windows API call SetClipboardData() to send data to the clipboard works fine with a project target framework of net8.0-windows. However, when I change the project to 'net9.0-w...

Beware of this issue if you were thinking of using .NET 9 for Windows apps.