If you're looking for a working PS2 BIOS file, it's under the emulator download here: https://vimm.net/?p=emulate
The message means that you need a valid BIOS, and that BIOS file at that link is valid.
"NintenDON'T sue me please haha"
For some reason the PCSX2 application won't recognize the ISO file in the folder selected, and I can't get past the first time configurations setting. I even switched the CDVD setting to Linuz ISO but it still doesn't recognize the Game ISO file. The message it tells me on the First Time Configuration states,"Please Select a Valid BIOS. If you are unable to make a valid selection please close the Configuration Panel."