You should replace your last line with the stock one to fix this bug.
Something clearly went wrong when you chose to replace your existing configuration with the maintainer configuration. Did you use an editor to do this, or did you select a choice in a dialog?
This last line is badly garbled:
GRUB_ CMDLINE_ LINUX=" splash #GRUB_DISABLE_ LINUX_UUID= true quiet"
The stock file in the package says:
#GRUB_ DISABLE_ LINUX_UUID= true
You should replace your last line with the stock one to fix this bug.
Something clearly went wrong when you chose to replace your existing configuration with the maintainer configuration. Did you use an editor to do this, or did you select a choice in a dialog?