Hello, In the past one-two weeks, I have been noticing arbitrary crashes when working in Org mode, with other packages like org-tree-slide and artist-mode. My guess is that this has to do with packages dealing with overlays. I do not have a reproducible recipe, but this time, I got the full backtrace (attached as gdb.txt). The log shows the the beacon package caused this. For reference, here is the source of beacon.el: http://git.savannah.gnu.org/cgit/emacs/elpa.git/tree/packages/beacon/beacon.el --- In GNU Emacs 27.0.50 (build 22, x86_64-pc-linux-gnu, GTK+ Version 2.24.23) of 2019-04-24 built on Repository revision: c5358e831f05cdd110f12a4260e6fb607c66c0b4 Repository branch: master Windowing system distributor 'Open Text', version 11.0.11505 System Description: Red Hat Enterprise Linux Workstation release 6.8 (Santiago) Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. C-c C-c is undefined Configured using: 'configure --with-modules --prefix=/home/kmodi/usr_local/apps/6/emacs/master '--program-transform-name=s/^ctags$/ctags_emacs/' --enable-checking=yes,glyphs --enable-check-lisp-object-type 'CPPFLAGS=-I/home/kmodi/stowed/include -I/home/kmodi/usr_local/6/include -I/usr/include/freetype2 -I/usr/include' 'CFLAGS=-ggdb3 -Og' 'CXXFLAGS=-ggdb3 -Og' 'LDFLAGS=-L/home/kmodi/stowed/lib -L/home/kmodi/stowed/lib64 -L/home/kmodi/usr_local/6/lib -L/home/kmodi/usr_local/6/lib64 -ggdb3'' Configured features: XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK2 X11 XDBE XIM MODULES THREADS PDUMPER GMP Important settings: value of $LANG: en_US.UTF-8 locale-coding-system: utf-8-unix -- Kaushal Modi