Visio cannot insert a new control because this file contains too many shapes, pages, or masters.
- Put all the controls on the page first before you add any other shapes.
- Put some placeholder shapes on the page first. These placeholders can be hidden or positioned off the page. When you want to insert a control, delete a placeholder, and replace it with the control. The new control will take the ShapeID for the placeholder that was deleted. And, this ShapeID will be less than 1024.
- Put as many shapes on background pages as possible to reduce the number of ShapeIDs.
- Create a new page, and then add all the controls that you want. Then, copy the original page contents to the new page. This process makes sure that the controls have the lowest possible number of ShapeIDs.