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

Are you using Client Profile as a project target? Consider this scenario:

Project A -> Project targets .NET Framework 4.0

Project B -> Project targets .NET Framework 4.0 Client Profile

Project A is referenced by Project B. Namespaces in Project A are not recognised in Project B.

If ths scenario matches, this is due to a target mismatch. Client Profile supports a subset of the BCL of the full framework. If an assembly is dependent on using the full framework (like requiring types from System.Web, etc.) then it won't be useable from an assenbly that only supports Client Profile.

Easy solution, change Project B to .NET Framework 4.0 (not Client Profile).