@LucMorizur isn't the error message showed inside of grub customizer? It should do that.
I can take a look at the resulting file when you're posting the contents of your /boot/grub/grub.cfg.new
@LucMorizur isn't the error message showed inside of grub customizer? It should do that.
I can take a look at the resulting file when you're posting the contents of your /boot/grub/ grub.cfg. new