Solving "Input Signal Out of Range" Error on Bootup

After installing Ubuntu, on restart, the error warning "Input Signal out of range" error can come up. To fix it, open a terminal and type...

gksudo gedit /etc/default/grub

... and unhash the line...

#GRUB_GFXMODE=640x480

 ... so it reads...

GRUB_GFXMODE=640x480

 ... or whatever resolution you desire, then save and exit the document.

Then type...

sudo update-grub