Vectorworks does not allow you to have objects the have the same name. Names in Vectorworks have to be unique. if you have been to one of my courses or watched a movie about viewports, you will have heard me say that the Viewport Name has to be unique. You cant have a viewport with the same name as a symbol or class.
I recently has a situation with a client where they cold not place a callout. In this movie i will show you the problem, then show you how to fix it.