Umm... delete all of those references and re-add them from the source. Makes no sense that would be happening.
What version of visual studio are you using?
The fact it can't locate "Systems.Numerics" strongly indicates there's something wrong with your C# install/version.
What version of visual studio are you using?
The fact it can't locate "Systems.Numerics" strongly indicates there's something wrong with your C# install/version.