So my ubuntu server failed to boot after a power outages. It just went into the boot menu. But no matter what I press, it have some error related to “need to load kernel first”. I went around with the error message, but none of the suggestions worked. Even using all the tools with boot-repair. Finally went back to this post. https://askubuntu.com/questions/397485/what-to-do-when-i-get-an-attempt-to-read-or-write-outside-of-disk-hd0-error

Most of the suggestions are correct, except this part ->

Grub> initrd /initrd.img

It happened that I don’t have /initrd.img. It maybe got removed somehow. But if I do initrd /boot/initrd.img* then I was able to boot. I will see if I have any more errors related to this.