Why is the library detached from the project...?

Question

C++ / C#

When you first start debugging. What are the options? Errors, except for the absence of elements, do not occur. All users are registered, and the library remains in the links, but it reacts as if the library is not in the project.
PS> VS 2010 Express (C#).

Answer 1

How is it connected? What is the library?
If there are no errors during compilation - how do you then find out that it, as you say, "unfastened"?