@bbdv I had the same problem. Midori has problems with ES6 and the arrow functions. I just deinstalled Midori and installed chromium-browser.
You can rewrite the startMidori.sh
#!/bin/sh
unclutter &
xset -dpms # disable DPMS (Energy Star) features.
xset s off # disable screen saver
xset s noblank # don’t blank the video device
chromium-browser --no-sandbox --disable-infobars --start-maximized --noerrdialogs --kiosk --incognito http://localhost:8080
If you want you can rename startMidori.sh to startChromium.sh, but don’t forget to rename it in the startMagicMirror.sh too.
My startMagicMirror.sh looks like this:
#! /bin/bash
cd ~/MagicMirror
node serveronly &
sleep 45
sudo xinit /home/pi/startMidori.sh