This question already has an answer here:
gedit /etc/default/grub output is:
GRUB_DEFAULT=0 GRUB_TIMEOUT=4 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor" GRUB_CMDLINE_LINUX=""
Let me know if u need more output. This happens like 1 out of 5 times. But I do not want this to happen anymore. Any help would be appreciated.