Inserting Gantt chart into regular flowchart

[cguin]

Last week I created a Gantt chart within a file containing multiple flowchart pages.

Now when I try to manipulate the Gantt Chart (e.g. Insert Column) I get the error message "This shape is not currently part of a Gantt Chart...."

Is there anyway to restore the Gantt Chart functionality?

Why did this happen / how can I avoid this in the future?

Thanks