Namespace not recognized (even though it is there)

Question

I am getting this error:

The type or namespace name \'AutoMapper\' could not be found (are you missing a using directive or an assembly reference?)

Answer 1

In my case, the referenced dll was build in higher version of .Net Framework. After I added the reference, I could use it. But as soon as I did a build, the 'missing reference' error will pop up. I refresh the dll the error will go but it would never build. This post made me check the framework version and thus I could resolve it by building the referenced project in same version.