then I repaired the GRUB using boot-repair
The instructions on the boot repair page specifically state that if you are unfamiliar with the Grub bootloader, to use the Create BootInfo Summary option and NOT try any repairs. You need to do that now as suggested if you still need help. The file that is not found is the primary windows boot file necessary to boot windows in EFI mode. You can easily check if that file exists by opening a terminal and using this command to output information:
Code:
sudo ls /boot/efi/EFI/Microsoft/Boot
If that file is not there or is corrupted, you will need some windows software to repair it. There are different possibilities as to what the problem is so you do need to post the boot repair summary.