Visual Studio saying name doesn't exist in current context
I've seen this error caused by differing versions of the .NET framework in the different projects. The Class Library I built was 4.5 and the application was 4.0, but the only error it gave was namespace errors. Changing the framework version on the class library and rebuilding it, then the application, resolved the error.
This can occur when namespaces, classes and variables become tangled when they have the same name. I have suffered with this before. Intellisense told me I was right, the compiler told me I was wrong! I trusted the compiler!
You have 2 options that I can think of
Search your code for Foo, and see it it is being used for something other than the static class.
Fully qualify the Foo.bar() call.
MyApplication.This.That.Foo.bar();
Do it in that order...it's better to elegantly resolve the issue so you can just call Foo.bar() as this is more readable and maintainable than having MyApplication.This.That.Foo.bar(); all over the place!
In my case I was missing a } at the end of one of the methods in the middle of the code which was causing the program not see the rest of the code and complain about the Methods I have defined after that point.