v-melonwang

@dmitrii-drobotov Verified on latest .NET 8.0.100-alpha.1.22567.28 build + private dll, this issue still reproduces. Error message does not contain this line "Use ControlAccessibleObject instead". Screenshot as below: 

@dmitrii-drobotov Thank you, verified on latest .NET 8.0.100-alpha.1.22567.28 build + private dll + replace System.Windows.Forms.dll in C:\Program Files\dotnet\packs\Microsoft.WindowsDesktop.App.Ref\[version]\ref\net8.0 folder, this issue was fixed. Error message contain this line "Use ControlAccessibleObject...

Verified on latest .NET 8.0.100-preview.2.23101.9, issue is fixed. Screenshot as below: **Win10:** HC #1 theme:  HC #2 theme:  HC Black theme:  HC White theme:  **Win11:** HC...

Verified this on .NET 8.0 TP build in Win11 22H2 & Win10 22H2 OS: 8.0.100-preview.6.23328.9, issue was fixed, result is same as above test result.

@Tanya-Solyanik I'm using .NET 5.0(5.0.17) that comes with VS.

The original issue was [9174](https://github.com/dotnet/winforms/issues/9174). Repro steps: 1. Create winform .NET 8.0 Core project 2. Change the TargetFramework from net8.0-windows to net9.0-windows in the csproj file 3. Add an ImageList...

@AngeloCresta Verified this in .NET 9.0.100-alpha.1.23580.4, issues https://github.com/dotnet/winforms/issues/9174 and https://github.com/microsoft/winforms-designer/issues/5233 were fixed when add above codes in .csproj file. https://github.com/dotnet/winforms/assets/94418985/d4a280dd-4d41-4bce-bfef-fdf3a177a639

@elachlan This issue also repro's in .NET9.0/8.0/7.0/6.0/5.0/3.1 and .NET framework app. https://github.com/dotnet/winforms/assets/94418985/c3a31d06-b5a0-4f4e-bc3a-431f6af9a17c