Getting “type or namespace name could not be found” but everything seems ok?

Question

I\'m getting a:

type or namespace name could not be found

error for a C# WPF app in VS2010. This area of code was compiling fine

Answer 1

We had a weird case of this that I just fixed in a solution. There was a hidden/whitespace character in front of a "using" statement in the main project. That project would build fine and the website worked fine, but the unit test project that referenced it could not be built.