Dear Visual Studio: Stop Adding "using System.Linq;" to everything!
"The type or namespace name 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference?)"
Really? That's neat because I never added Linq in the first place! Visual Studio did!
Every single new class contains "using System.Linq" - which is pretty stupid because, amazingly enough, not every class needs to work with databases.
To compound the stupidity, new projects do not contain an assembly reference to System.Linq - which generates this warning.
Stupid Visual Studio. Now to hunt for a way to stop it from trying to use System.Linq in every new class file. (Which, annoyingly enough, includes forms.)