I was able to get hold of the Graphics object by casting the Graphics3D object as Graphics3DGdiPlus and using that class's Graphics property. Our drawing routines now work great with the most recent version of the dll. I have been able to duplicate the issue with the unhandled exception in DrawLine....

I am experiencing a problem when a DrawLine tool is active and a user has a context menu displayed at the same time as a DrawLineItem is selected. The problem occurs when the user accidentally clicks the left mouse button and moves the mouse slightly while the right mouse button is held down. The ap...