Maybe you don't know the proper way to boot games perhaps, if so.
First, go to CDVD and then go to "ISO selector" and hit browse, then find the ROM and hit "open". Then hit boot full/fast on "System" if the game hasn't run yet and you should be all good to go.
If that's not your problem then maybe you have an incompatible or bad "Bios" file to run the game.
Go to the emulation lair for Pcsx2 and click the red words "PS2 Bios" and then download them and use it instead.
"Everyone is flawed one way or another, even the best of us, so why bother being Insecure "
I've been wanting to play Kingdom Hearts and persona 4 again but we sold our ps2 so I tried using the roms here and they dont work. I tried using 1.4.0 and 1.6.0, I used 7 zip to extract them, and I messed around with the settings too. I could use some help.