New Post: Prism 4.2 Errors with Prism Library Solution

I've downloaded and installed Prism 4.1 and the Prism 4.2 for .Net 4.5, where I have copied the contents of source.zip into my unpacked folder (which is where Prism 4.1 was installed). I've followed, or rather following the readme which states to load the Prism Library Solution and build it prior to running the Quickstarts. However, I'm getting 1 error and 21 warnings, my error being:

Assembly 'Microsoft.Practices.Prism.Interactivity, Version=4.2.0.0, Culture=neutral, PublicKeyToken=null' uses 'System.Windows.Interactivity, Version=4.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' which has a higher version than referenced assembly 'System.Windows.Interactivity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' c:\Prism\unpacked\PrismLibrary\Desktop\Prism.Interactivity\bin\Debug\Microsoft.Practices.Prism.Interactivity.dll Prism.Interactivity.Tests

How can I resolve this please?