Reference DLLs not loading in Visual Studio 2010

Question

I\'m working on a C# 4.0 project in VS2010 and needed to use some older DLLs containing controls that were created in C# 3.5 on VS2008. When I first add the DLLs to the ref

Answer 1

I tried Build->Clean Solution and then could add the reference.

Answer 2

Turns out that it was something to do with VS2010 defaulting to the .NET 4 client profile, as soon as I changed it to the regular profile it built fine. There's a day wasted...

Answer 3

view the target framework.. in my project, was 4.0 client profile, e the reference dll was in 4.0

Answer 4

I used to have similar problem, but the profiles were not the issue, so the problem was that my class library use a special NuGet package that has Dependency... so I install the dependency package in the target project and added the project reference and works!

But I am not sure if there is a better solution for this problem??? for me VS should be smart enough to carry those dlls along with the references. (I already verified that "Copy Local" is set to True)