Hello Simon Cruickshank, Since your bug report shows crashing when accessing X11 I'm going to assume you're using a Wayland based session (like GNOME). Your bug report is most likely a duplicate of one that already mentiones a workaround (and just got a patch posted), See:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=861603 Regards, Andreas Henriksson
