Error adding dll file into Setup Project

Question

I'm using Visual Studio 2008 to create a new Setup project. I'm trying to add a file (dll) to the Application Folder, there is nothing else in the project or in the solution.

But I get a way too generic error : The operation could not be completed

Answer 1

Well, I fixed it. I was adding a DLL file created with VS2013 and .NET 4.5. I tried to re-create the project with VS2008 and used the new dll and it worked.