#on I386 and AMD64
#to disable apparmor totally on Debian:
sudo mkdir -p /etc/default/grub.d
echo 'GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT apparmor=0"' | sudo tee /etc/default/grub.d/apparmor.cfg
sudo update-grub
#sudo reboot

#==================
# WIth armbian, since there's no grub, adding to armbianEnv.txt
extraargs=apparmor=0
#and rebooting
------------------
evince not starting
it's Apparmor's fault, and due to my home directory being outside /home
fix was to edit /etc/apparmor.d/tunables/home.d/local and add the line
@{HOMEDIRS}+=/elsewhere/home/


Source:
https://unix.stackexchange.com/questions/42385/evince-fails-to-start-because-it-cannot-read-xauthority