I've found out what my problem was.

First my window is destroyed (and effectly set the hwnd to 0...).

then i start deleting my panes and all frames and windows atteched to them. This results in the crash.

 

I made the VB by hand, resulting in the same situation: frst the window is destroyed, then the pane(s).

 

After changing the order (first the pane, then the window) the problem is solved.

Guess you call DestroyPane for same pane twice. Please attach this VB sample that crash

 

I have a problem with cleaning up the Panes.

 

I create 3 panes , with 1 docked to the right, and the other 2 below the first.

 

   ASSIGN h_Pane = ch_DockingPane:CreatePane( 1, 150, 100, 1 /* Right  */, ? ).
   ASSIGN h_Pane = ch_DockingPane:CreatePane( 2, 150, 100, 3 /* Bottom */, h_Pane ).
   ASSIGN h_Pane = ch_DockingPane:CreatePane( 3, 150, 100, 3 /* Bottom */, h_Pane ).

   /* Use them */
  

then for the first 2 i create a frame and set the handle (third is not used at this moment, still developing).

 

After the program is done, i want to clean it all up:

   /* Clean up */
   DO WHILE ch_DockingPane:PanesCount > 0:
      ASSIGN h_Pane = ch_DockingPane:FindPane( ip_ID ).
      IF NOT VALID-HANDLE( h_Pane ) THEN
         next.

 

      MESSAGE 'Cleaing up number: ' h_Pane:ID.

 

      ch_DockingPane:DestroyPane( h_Pane ).
   END.
  
  

But: I get the message 'Cleaing up number 3:' and then my applicatyion crashes.

What do i do wrong?

 

BTW. This is written in Openedge, but using the same kind of code in VB also crashes VB????