Windows Phone 7.1 - System.Windows.Interactivity assembly not found.

Wolfgang Ziegler's Avatar

Wolfgang Ziegler

04 Aug, 2014 01:20 PM

I am trying to build a Windows Phone 7.1 Silverlight Project, which references the "System.Windows.Interactivity" assembly.
This results in a build error:

warning MSB3245: Could not resolve this reference. Could not locate the assembly "System.Windows.Interactivity, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL". Check to make sure the assembly exists on disk.

error CS0234: The type or namespace name 'Interactivity' does not exist in the namespace 'System.Windows' (are you missing an assembly reference?)

Building the project for Windows Phone 8 (other version of the Interactivity assembly) work. Any ideas?

  1. Support Staff 1 Posted by Feodor Fitsner on 04 Aug, 2014 01:42 PM

    Feodor Fitsner's Avatar

    Hi Wolfgang,

    Phone 7.1 project is in Silverlight 4, right?

  2. Support Staff 2 Posted by Feodor Fitsner on 04 Aug, 2014 01:54 PM

    Feodor Fitsner's Avatar

    OK, found it. The v3.8.5 of this assembly is a part of Windows Phone SDK 7.1 and its location on build worker is C:\Program Files (x86)\Microsoft SDKs\Expression\Blend\Windows Phone\v7.1\Libraries\System.Windows.Interactivity.dll

  3. 3 Posted by Wolfgang Ziegle... on 04 Aug, 2014 01:54 PM

    Wolfgang Ziegler's Avatar

    Hi Feodor,


    Yes it’s Silverlight 4.


    Thanks for the quick reply!

  4. 4 Posted by Wolfgang Ziegle... on 04 Aug, 2014 02:01 PM

    Wolfgang Ziegler's Avatar

    That’s the same path as on my local machine. Not sure why it doesn’t work then …

  5. 5 Posted by Wolfgang Ziegle... on 05 Aug, 2014 08:09 AM

    Wolfgang Ziegler's Avatar

    I was able to resolve this issue using a <HintPath> for my <Reference> to System.Windows.Ineractivity.

        <Reference Include="System.Windows.Interactivity, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
          <HintPath>$(MSBuildProgramFiles32)\Microsoft SDKs\Expression\Blend\Windows Phone\v7.1\Libraries\System.Windows.Interactivity.dll</HintPath>

  6. Support Staff 6 Posted by Feodor Fitsner on 05 Aug, 2014 08:10 AM

    Feodor Fitsner's Avatar

    Great, thanks for the update!

  7. Ilya Finkelshteyn closed this discussion on 25 Aug, 2018 01:46 AM.

Comments are currently closed for this discussion. You can start a new one.

Keyboard shortcuts


? Show this help
ESC Blurs the current field

Comment Form

r Focus the comment reply box
^ + ↩ Submit the comment

You can use Command ⌘ instead of Control ^ on Mac