Error: Microsoft SharePoint is not supported with version 4.0.30319.1 of the Microsoft .Net Runtime.  

The SharePoint Foundation 2010 object model is not accessible using the .NET Framework 4 (or later). Calling any object or method in the object model using any framework version other than .NET 3.5 will throw the above exception.   It is possible to access the SharePoint objects using the web services interface from your .NET 4 application, but this will only allow limited functionality of the complete object model.