Managing Assemblies for c# components

Hello people, so I got an assembly for managing data of certain objects, to keep a link and order throughout my definition.

I keep the Assembly.dll inside of the same folder as the project, just so you guys know.

So, sometimes I duplicate the folder, just to keep a backup of my previous work (this folder includes the Assembly.dll), but when I open the new file, it kind of keeps referencing the past Assembly.dll from the pre-duplicate folder, any ideas why?

To make things clearer, imagine having Folder A, with rhino, grasshopper and Assembly.dll. If i duplicate this and make Folder B, the c# scripts inside grasshopper will still reference the .dll inside of the Folder A.

I just want to make a relative path or something that helps me keep the reference to the Assembly.dll inside the same folder.