error opening xaml files in Visual Studio 2010

[myen]

Every time that I try to open an xaml file in VS2010, I get the following error message and nothing shows in the designer:

Could not load file or assembly 'Microsoft.Practices.Prism, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)

Someone please advise what is the cause of this and how to resolve this issue.

[Stelzi79]

I think you miss a required assembly. See http://msdn.microsoft.com/en-us/library/gg406140.aspx under System Requirements. You probatly need the "Silverlight 5 Tools for Visual Studio 2010". When you download and install this Toolset then you won't get any errors any more.

[emre]

Can you build solution?

[myen]

I have tried your suggestion and getting some of the xaml files to open but pages like shell.xaml, app.xaml, common.xaml STILL not opening in design view.

[stanleysct]

Ya, me too. I use Visual Studio 2012 also cannot open in design view. Any solution???