In reply to oldmouldy:
In reply to Rich103:
You could try deleting and re-adding the via. OrCAD Layout only allowed 16 vias to be defined, sounds like only one was defined to restrict routing vias to one definition.
OrCAD Layout 9.0 was supported on 95 / 98 and NT4 versions of Windows, and it's unlikey that you are still running a machine with those configurations so, unfortunately, should you press OK and the disk gets formatted as a consequence, nothing can be done about it. I suggest that you look into some more modern tools that will provide more functionality and reliability for your work.