Before I disabled the ACPI (because it is not supported by Ubuntu) Ubuntu can't boot (obviously!)
At that time when I boot Ubuntu, I always get these 2 messages. After 1 of those message shows, nothing shows up.
error: "prefix" is not set error: "prefix" not found
Although my problem is solved, I just want to know what these 2 messages mean in general, like what makes GRUB show this message. Espically the "prefix" part.