Sorry, I don't know what is wrong here.
You could try to build a .NET 4 or 4.5 version of the core library (there is a .NET 3.5 project you can start from) and see if the errors disappear.
You could try to build a .NET 4 or 4.5 version of the core library (there is a .NET 3.5 project you can start from) and see if the errors disappear.