Comment 3 for bug 888281

This also happens when changing the root.disk (e.g. through a custom boot entry). In my case, I added a custom menu entry to boot a copy of my root.disk (new.disk). First time I select it I get the "You have to load the kernel", hit Enter to return to the grub menu. If I then select the custom entry it boots fine. If I didn't select the custom entry (i.e. the normal root.disk) I get the same error, and then after returning it boots.

So it seems to be the act of replacing the loop device that causes the issue.

I'll try experimenting. e.g. does the initial loop device have to be the same as the one in the menu entries? I'll play around a bit and see if I can get a workaround.