1. Target Framework .NET6 and VS 2022 17.0.1:
2. Install UI.for.WinForms.AllControls.Net60 version 2021.3.1123:
3. Double click the form to open the designer:
4. First try dragging a RadGridView from the toolbox:
5. Install the Nuget package for the toast notification:
6. Install Microsoft.Toolkit.Uwp.Notifications version 7.0.0:
Please make sure that the C:\Program Files (x86)\Progress\ToolboxNuGetPackages folder doesn't contain anything and it is empty. If there is any version available there, please delete it.
7. Now, try opening the designer. It never loads: