Executing 'grub-install dummy' failed.

[MEGADETH]

I am have done everything as you show but it still show input/output error please somebody help😭😭😭🙏🏻🙏🏻🙏🏻

i try all the same and don't work for me.. (grub screw all after try to upgrade my kali)..

finaly, run usb on rescue mode.
try to force install grub on efi partition > failed, fatal error
try to instal grub on /dev/sda > failed, fatal error

run command line on /dev/sda1 (my kali partition)
#mount /dev/sda3 /boot/efi -o rw
#update-initramfs -u
#update-grub
detect all systems (kali, slackware, w10, debian jessie on my laptop) and write all data on EFI sys.
#reboot
and this work for me.-