You drag a shape on a diagram but the p4b-object is not created: object properties are not opened.
Check that you have a class with the name exactly like the name of the shape. To be sure, copy the name of the shape, go to the Designer and paste the name of the shape in the class name. Save the stencil, save the diagram, close and open it again. Try to drag the shape on the diagram. If this does not solve the problem, than see point 2.
Open the diagram. Select Developer tab and click on Document Stencil.
Delete all shapes in the Document stencil.
Close the document stencil, save the diagram, close and open the diagram. Try to drag a shape. It should work now.
Reason (for point 2)
Most probably you have opened an existing diagram with shapes on it, edited the master shape and then tried to put the shape (of changed master shape) on the diagram. So there are 2 different shapes for one class: your old shape and your new shape. You should delete old shapes in the cash (document stencil) to work properly with process4.biz.