Could not load system.spatial

I have an MVC 4 solution and it works perfectly at home ie I can run it and the page loads etc.

I have brought it to college today to contiune work on it and when I debug the page I get the following error.

Could not load file or assembly 'System.Spatial' or one of its dependencies. Strong name signature could not be verified.  The assembly may have been tampered with, or it was delay signed but not fully signed with the correct private key. (Exception from HRESULT: 0x80131045)

Can any one offer some solutions.

System.Spatial is an assembly that is part of the WCF Data Services. You will need this installed on workstations you'll be developing on since it appears you are using it. You can download the tooling from Microsoft, but requires Visual Studio 2013.