Hello my friends, I've come to this forum because I've been wanting to find an answer to this situation I've been in for months.

In MESS (version 0.185), even with all the right BIOS in the folder, I still cannot get the emulator working because it gives me the same "this device is missing one or more ROM or CHD files"

The emulators I'm having trouble with are;
-Hurtang Game Master/Systema 2000
-Bally Astrocade
-Mega Duck/Cougar Boy
(Side note: Mega Duck will just show a green screen when I try to load it.)
-Super Cassette Vision

What can be done about this? I've been searching for answers for months now but all the answers that I've received haven't helped.