The popup menu appears with the top just visible at the bottom of the screen. Resizing the emacs window approximately to the top half of the screen will make the menu visible far below the main emacs window. All modeline menus behave this way.
Terminal output from emacs start: ------------------------------------- *** BUG *** In pixman_region32_init_rect: Invalid rectangle passed Set a breakpoint on '_pixman_log_error' to debug
*** BUG *** In pixman_region32_init_rect: Invalid rectangle passed Set a breakpoint on '_pixman_log_error' to debug
*** BUG *** In pixman_region32_init_rect: Invalid rectangle passed Set a breakpoint on '_pixman_log_error' to debug
------------------------------------
In GNU Emacs 24.5.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.18.7) of 2016-02-03 on buildhw-05.phx2.fedoraproject.org Windowing system distributor `Fedora Project', version 11.0.11801000 System Description: Fedora release 23 (Twenty Three)
Important settings: value of $LANG: en_DK.UTF-8 value of $XMODIFIERS: @im=ibus locale-coding-system: utf-8-unix
Major mode: Lisp Interaction
Minor modes in effect: tooltip-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t
Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Making completion list...