No problem, it's very easy to reproduce. It comes from the very special nature of the console, contrary to other dialogs in the interface, it always exists, but since the interface has a parent system to be able to draw the background, it can create problems when the parent of the console disappears. Here because of the error, it takes one of the temporary messageboxes as parent and so the 1st time you try to display it, it just crashes because the parent has disappeared !
Yeah it's normal, this part of the gui is a hack, because I wanted the console to always exist, which is not the normal way of working for this gui.
So there is a workaround, not too complex, maintain a list of active dialogs to be able to check if the parent is still active when drawing a dialog. If it's not, just remove the parent that's all. So patch very short and efficient.
Pushed to git.