It stops at the grub rescue> prompt. 2 errors before grub rescue. 1 no such device: 00774dcb-466b-4964-acdd-e56d75c818d9. 2 unknown filesystem. Entering rescue mode... Only command allowed is ls, (hd0) (hd0 ,gpt5) (hd0 ,gpt4) down to gpt1 then (hd1).