I created the library using Version 16.9.4 as a .NET Framewok Library class. I am now using version 16.9.5. To add the Reference, I clicked on References in Solution Explorer and a window appeared that showed a long list of possible references. I found System.Drawing in this list, clicked on the box opposite this and closed the window. I checked that System.Drawing appeared in the list of references for the application. I have also looked at Project->add a reference, and the same list appears, with the box checked. I have Imports System.Drawing at the head on my code for this class.