I have now managed to reproduce this bug.  To reproduce:

Compile sample graphical application.
Undock Output tab and move it below main window.
Undock Diagram tab and dock it in upper half of Output window.
Undock Class tab and dock it in zone with Diagram.
Undock Feature Relation tab and dock it in zone with Output window.
At this point, there is one zone below main window with 

   Upper half tabs: Diagram, Class
   Lower half tabs: Output, Feature

Undock Dependency tab and move it to right of zone with the above four tabs
   and below main window.
Click on title bar at very top of zone containing Diagram, Class, Output and
   Feature tabs (this title bar is not labeled), and move the entire zone
   so that the outline box covers the entire undocked Dependency window.
Estudio crashes with the previously attached trace.