Property "Command" does not have an accessible setter

[Pierre]

I can't get rid of a XAML designer error.

<UserControl x:Class="MenuItemBinding.SomeUserControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation">
   <Grid>
      <telerik:RadMenu>
         <telerik:RadMenuItem Header="Hello World" Command="{Binding HelloWorld}" />
      </telerik:RadMenu>
   </Grid>
</UserControl>

 

 The 'Command="{Binding' part has a green underline with the tooltip "The property "Command" does not have an accessible setter".

Observations:

• Only happens in x64 (x86 doesn't show this error).
• Seems to only happen with RadMenuItem although I have not check all cases.
• It happens regardless where I place the RadMenuItem in the XAML.
• The application still works fine even though the XAML designer is stuck to "Invalid Markup"

How do I get rid of this error?

[Nasko]

Hi Pierre,

Since the release of Visual Studio 2015 (which we believe you are using) we have hit several issues with its designer. We isolated and reported most of them to Microsoft. One of these issues is the one you are currently observing:
https://connect.microsoft.com/VisualStudio/feedback/details/2006584/designer-error-the-property-command-does-not-have-an-accessible-setter-for-a-control-implementing-icommandsource-in-wpf-application-with-x64-platform-target

In the comments Microsoft stated that fix should be available with the next update of VS 2015.

Hope the provided information will be helpful for you.

Regards,
Nasko
Telerik