I am using MS Project 2010. I am attempting to insert a column to a Gantt view on a project plan I've been working with for about 10 months now. I insert and hide columns all the time from this view. Today, when I try to insert a column, I get the message: You cannot modify a table usint the TableEdit method in a view that is not a sheet view. I have no issues adding/hiding columns to other project plans... just this one. Any ideas?