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VS 2012 XML Design time error


When using this with VS 2012 I get this design time error: "The type 'EventToCommand' from assembly 'GalaSoft.MvvmLight.Extras.SL5' is built with an older version of the Blend SDK, and is not supported in a Silverlight 5 project." I installed the package, but My assemblies are still versioned I miss something?
by thomasfj on Today at 11:46
Closed Oct 13, 2014 at 1:59 PM by lbugnion


lbugnion wrote Oct 24, 2012 at 11:20 AM


This is correct, Microsoft released a new version of System.Windows.Interactivity and because it is strongly signed, every depending assembly needs to be rebuilt. I am working on it, will publish a fix in a few days.

Sorry for the inconvenience

onovotny wrote Nov 11, 2012 at 4:06 PM

This issue is not present in the PCL version as it already uses the newest interactivity package.

lbugnion wrote Nov 11, 2012 at 10:53 PM

Actually this is solved in V4.1. Download from I will make the DLLs available on Nuget next week.

adhemar82 wrote Nov 13, 2012 at 10:07 PM

I'm using version MVVM Light (via NuGet) and I'm still seeing this error on Visual Studio 2012 in a WPF project. Should this be resolved?

The event to command binding works fine at runtime, by the way. Just the designer is complaining.

VincMan wrote Dec 5, 2012 at 8:33 AM

I'm still having this issue too. V. (downloaded here yesterday), VS2012, WPF project, runtime fine, designer not.

"The type 'EventToCommand' from assembly 'GalaSoft.MvvmLight.Extras.WPF45' is built with an older version of the Blend SDK, and is not supported in a Windows Presentation Framework 4 project."

DarkPrisma wrote Mar 5, 2013 at 9:39 AM

I have the same issue in

VincMan wrote Mar 8, 2013 at 9:01 PM

It now works after I have installed the "Visual Studio 2012 Update 2 CTP". See

metacircle wrote Mar 12, 2013 at 5:04 PM

Hi Laurent,

this is still happening with VS2012 and the latest MVVM Light NuGet package (

lbugnion wrote Mar 12, 2013 at 6:50 PM


It works fine now but you need the Update 2 of Visual Studio 2012. The error is due to a bug in Visual Studio and Update 2 fixes it.


metacircle wrote Mar 17, 2013 at 1:55 PM

Thank you for the information. I will have to wait until my company rolls out this update then. At home it is working fine now.