AutoPLANT Add field to Piping Table on SQL

Hi, I am using AutoPLANT V8i SS4. I want to add a new filed to the piping table. Went in through project admin, highlighted PROJDATA and clicked Edit Tables. In PROJDATA, picked Piping (3D Piping Data) and clicked on Edit and then Table Design Comes back with a message as below even though dbo.PIPING Table is there.

I have Access 2010 loaded on my pc