Ubuntu does not put Fedora into GRUB menu
After a software update for Ubuntu, my dual boot with Fedora will not show Fedora in the start menu. It just boots into Ubuntu and when I hold Shift and boot, it only has Ubuntu in the list.
I have tried the post about installing grub-customizer but when I run that, I get
Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package grub-customizer
I cannot find any other way to fix this problem. I am a complete newbie to Linux.