报错信息如下：

error: file '/grub/x86_64-efi/normal.mod' not found.
Entering rescue mode...
grub rescue>

Ubuntu系统解决办法：

grub rescue >ls
(hd0) (hd0,gpt6) (hd0,gpt5) (hd0,gpt4) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) (cd0)
grub rescue> set root=(hd0,gpt7)/boot/grub
grub rescue> set prefix=(hd0,gpt7)/boot/grub
grub rescue> insmod normal
grub rescue> normal

Debian系统解决办法：

grub rescue >ls
(hd0) (hd0,gpt2)/boot/grub
grub rescue> set prefix=(hd0,gpt2)/boot/grub
grub rescue> insmod normal
grub rescue> normal

最后输入命令：reboot重启即可！