Hi, I doubt that my modification will change anything related to this. However, I noticed that a number of NextStep callback functions start with the following code sequence: if (!emacsframe->output_data.ns) return; If `ns' is NULL it would account for the crash. I don't see why we can't add it to the windowDidResize: method as well. Finally a reservation, I'm still learning the NS code base and I don't know under which circumstances the `ns' field is NULL. -- Anders On Thu, Oct 22, 2015 at 8:14 PM, martin rudalics wrote: > > > extra = FRAME_NS_TITLEBAR_HEIGHT (emacsframe) > > + FRAME_TOOLBAR_HEIGHT (emacsframe); > > Ahh, so this is Emacs 25. Strange. Rainer what do > > p emacsframe->output_data.ns->titlebar_height > > and > > p emacsframe->output_data.ns->toolbar_height > > give in frame#0 of the debugger? > > martin