1. emacs -Q 2. C-z The window mimizes and then Emacs crashes. This only happens on Mac OS X 10.11 (100% of the time). I just tested on 10.10 and I couldn't get it to crash. It only happens in ns mode ("emacs -nw" works fine). I don't have a gdb backtrace, but I have attached an OS backtrace (backtrace-1.txt). I also received a backtrace from someone else having the same problem. Their backtrace (backtrace-2.txt) is similar but shows what looks like a NULL pointer function call. -David In GNU Emacs 24.5.1 (x86_64-apple-darwin13.4.0, NS apple-appkit-1265.21) of 2015-04-10 on builder10-9.porkrind.org Windowing system distributor `Apple', version 10.3.1404 Configured using: `configure --with-ns '--enable-locallisppath=/Library/Application Support/Emacs/${version}/site-lisp:/Library/Application Support/Emacs/site-lisp'' Important settings: locale-coding-system: utf-8-unix Major mode: Fundamental Minor modes in effect: auto-insert-mode: t show-paren-mode: t global-auto-revert-mode: t delete-selection-mode: t tooltip-mode: t electric-indent-mode: t mouse-wheel-mode: t file-name-shadow-mode: t global-font-lock-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t buffer-read-only: t size-indication-mode: t column-number-mode: t line-number-mode: t transient-mark-mode: t Recent messages: Loading delsel...done Loading autorevert...done Loading gnus...done Loading paren...done Failed to enable theme: calmer-forest My .emacs loaded in 0.000000s My .emacs loaded in 0.418803s For information about GNU Emacs and the GNU system, type C-h C-a. Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug calmer-forest-theme ack-and-a-half-autoloads flymake-css-autoloads flymake-cursor-autoloads flymake-haml-autoloads flymake-jslint-autoloads flymake-perlcritic-autoloads flymake-php-autoloads flymake-ruby-autoloads flymake-shell-autoloads go-mode-autoloads magithub-autoloads mode-compile-autoloads nav-autoloads rainbow-mode-autoloads info slime-autoloads svg-clock-autoloads package epg-config commit-patch-buffer pcase log-edit easy-mmode message sendmail format-spec rfc822 mml easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045 ietf-drums mailabbrev gmm-utils mailheader ring pcvs-util add-log vc vc-dispatcher david-custom-emacs-setup advice david-headers autoinsert ginel-string david-keys david-movement edmacro kmacro david-coding-style saveplace paren gnus gnus-ems nnheader gnus-util mail-utils mm-util help-fns mail-prsvr wid-edit cl-loaddefs cl-lib autorevert filenotify delsel cus-start cus-load benchmark time-date tooltip electric uniquify ediff-hook vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment lisp-mode prog-mode register page menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote make-network-process cocoa ns multi-tty emacs) Memory information: ((conses 16 161195 16306) (symbols 48 25173 0) (miscs 40 89 203) (strings 32 36358 13087) (string-bytes 1 954275) (vectors 16 22379) (vector-slots 8 1210585 203755) (floats 8 97 52) (intervals 56 241 8) (buffers 960 12))