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

1.remove the reference and add it again 2.Close the solution and re-open it 3.Create a new solution and add all old ones in it

Answer 2

Check your DLL,s .NET version and your host project's . NET version. Most probabbly there are different and somehow it creates problems in your specific case.

Regards.