/Usr/Sbin/Grub-Mkconfig: 1: /Etc/Default/Grub: : Not Found

I'd found an answer for a problem and fixed it in /etc/default/grub, but now when I try sudo update-grub it comes this error: /usr/sbin/grub-mkconfig: 1: /etc/default/grub: : not found

This is my grub file:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=-1
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.alpha_support=1"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
# GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
# GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
# GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
# GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#G RUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
# GRUB_INIT_TUNE="480 440 1"

Appreciate any and all help.