KryptonForm not showing in designer - Visual Studio 2013

Question

I've added the toolkit.dll as a reference, inherited KryptonForm instead of Form, successfully built the application, everything is working fine, but designer mode fail to display the form. I am getting this error:

Could not find type 'ComponentFactory.Krypton.Toolkit.KryptonForm'. Please make sure that the assembly that contains this type is referenced. If this type is a part of your development project, make sure that the project has been successfully built using settings for your current platform or Any CPU.

Answer 1

I found the issue: I renamed the dll thinking that will not affect in any way the application, and it didn't ! But somehow affects the designer: when I renamed the dll back to ComponentFactory.Krypton.Toolkit.dll Visual Studio's designer worked aswell. I am curious why behaves this way