When booting, I get an err or message...

error: 'File /EFI/grub/xen-4.5.2_04-9.efi not found'

homer:/boot # find . -name '*.efi'
./grub2/x86_64-efi/core.efi
./grub2/x86_64-efi/grub.efi
./efi/EFI/opensuse/grubx64.efi
./efi/EFI/opensuse/shim.efi
./efi/EFI/opensuse/MokManager.efi
./efi/EFI/opensuse/grub.efi
./efi/EFI/opensuse/xen-4.5.2_04-9.efi <=== because it's installed there instead
./efi/EFI/boot/bootx64.efi
./efi/EFI/boot/fallback.efi
./efi/EFI/grub/shim.efi
./efi/EFI/grub/MokManager.efi
./efi/EFI/grub/grub.efi
./efi/EFI/grub/grubx64.efi

Whatever is wrong, the solution is NOT as simple as moving the bloody thing to
/boot/efi/EFI/grub.  Doing so fixes up the missing file error message, but the
screen then just blinks, and I'm right back to the boot menu.

Box is multiboot 42.1, 13.2, and Windows 10 if that matters.