I've duplicated this problem - installing on a FAT32 partition with size > 4GB. This creates a separate usr.disk and this seems to be resulting in a problem in processing grub.cfg when loop0 is reset from usr.disk to root.disk.
I've duplicated this problem - installing on a FAT32 partition with size > 4GB. This creates a separate usr.disk and this seems to be resulting in a problem in processing grub.cfg when loop0 is reset from usr.disk to root.disk.