Messed up my bootloader, not sure how to fix.

[robertwigfield]

A few minutes ago I had the bright idea to install the Multibeast settings to my disaster boot drive, which I did, and made sure that multibeast installed them to that drive and no other. I rebooted to test it, and now all I get is this:

Fine, I'll just boot off my USB flash drive (which I am doing now so I can use my computer) and reinstall just Chimera to my boot drive, did that, still getting the boot error.

What do I have to do?

AM

The fix to this does not have to do with an actual "BOOT0" fix. When you installed the MultiBeast settings, I'm guessing you unattached some of your drives. When doing this, it resets your boot order set in your BIOS. Go into your BIOS, and switch your OS X drive (NOT THE UEFI ONE) to be first in your boot sequence.
Basically, by disconnecting those drives, you have reset the boot order, causing your boot drive to not be first in your sequence.