I'm trying to run an appliaction, but when I run it I get a
Could not open display `(null').
Error. Why is this? Specifically I was trying to run scratch (which I installed via aws):
root@ip-10-251-56-90:/usr/bin# ./scratch
Executing: /usr/lib/squeak/4.4.7-2357/squeakvm -encoding UTF-8 -vm-display-x11 -xshm -plugins /usr/lib/scratch/plugins/:/usr/lib/squeak/4.4.7-2357/ -vm-sound-ALSA /usr/share/scratch/Scratch.image
Could not open display `(null)'.