I tried iso9660.mod from grub-efi-amd64-bin 2.00 from snapshot.debian.org and that hung as well.
I also tried installing grub-efi-ia32 instead of grub-efi-amd64 but that also hung.
I tried iso9660.mod from grub-efi-amd64-bin 2.00 from snapshot.debian.org and that hung as well.
I also tried installing grub-efi-ia32 instead of grub-efi-amd64 but that also hung.