Have you tried to clearing the Toolbox cache, which is created by Visual Studio? The following steps will help you to clear the toolbox cache:
- Close all Visual Studio instances;
- Open Windows Explorer and navigate to the directory %localappdata%\Microsoft\VisualStudio\[VisualStudio Version]
- Make sure that the option 'Show hidden files...' is selected in the Windows Explorer options;
- Delete all *.tbd files;
- Start Visual Studio and use the Toolbox Configurator wizard to set the required controls version.
Please let us know if the issue still occurs.
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