Hi NiLuJe,
in your latest build, there's obviously a problem in KUAL Helper's "menu.json" file ... the single quotes around 'KindlePaperWhite4' seem to be not correct

- see attached exaple of logfile which is created every time I launch KUAL helper:
Code:
KUAL: ***** started v2.7.12-g9623dd8 (20181108,a) on Mon Nov 19 15:08:31 GMT-6:51100 2018
KUAL: "/mnt/us/extensions/helper": JSON "if": "KindleTouch" -m "KindlePaperWhite" -m "KindlePaperWhite2" -m "KindleBasic" -m "KindleVoyage" -m "KindlePaperWhite3" -m "KindleOasis" -m "KindleBasic2" -m "KindleOasis2" -m 'KindlePaperWhite4' -m || || || || || || || || || : invalid expression
KUAL: "/mnt/us/extensions/helper": JSON "if": "KindleTouch" -m "KindlePaperWhite" -m "KindlePaperWhite2" -m "KindleBasic" -m "KindleVoyage" -m "KindlePaperWhite3" -m "KindleOasis" -m "KindleBasic2" -m "KindleOasis2" -m 'KindlePaperWhite4' -m || || || || || || || || || : invalid expression