AutoCAD: Why can’t I see discontinuous lines in paper?
Working with external references is always trick with AutoCAD so I know how frustrating these little nuances can be. I suggest checking out the layers in both the file you’re working on as well as the original referenced file. If a line is under the Defpoints layer, it sometimes won’t be visible when printed. Try to tweak the layer settings if that’s the case or just assign the lines a new visible layer.