Updating DLL's

Question

Good morning,

I have a set of DLL's for a C# console application that was created 2 years ago.

I need to make changes to one of these DLL's. I have made the changes but when I try to run the application, it says it cannot load one of the projects referenced strangely not in the DLL I changed but in another one.

I have rewritten the DLL using the IDE in which the DLL was originally written but that does not resolve the issue.

Any idea how I could resolve this?

Thank you.