Reference added but Namespace is not recognized

Question

I added a DLL to my project. The DLL contains the namespace test.security. Now, test.security is not recognized. Why is this?

I am using this DLL in oth

Answer 1

It often depends on what is in that namespace; for example, if nothing is in there then the namespace doesn't really exist.

It is also possible that you are missing some other dependency which means that the compiler can't use (until the reference is added) any of the types in that namespace (for example, if the types in that namespace all depend on some type from Another.dll, and you haven't referenced Another.dll).

It is possible you have referenced the wrong version of the dll, and the version you are referencing doesn't have that namespace.

It is possible the compiler is already telling you about a reference problem, meaning it can't use it - look in the errors/warnings list. For example, it could be a physically missing file, or a .NET version mismatch, or a strong-naming issue, that means it can't use the reference.