PPSSPP Doesn't See my ISO

[GentleBim]

So, I already did multiple searches on this topic, and I didn't see anything. This forum is ginormous, so I hope I didn't miss one. In the event that this has been asked already, and I just didn't see it; sorry.

I just downloaded PPSSPP onto my Galaxy SI. I made some ISOs of my own games, and I transferred them over to my SD card. However, PPSSPP doesn't see them. I looked at the user guide, but it seemed like everything I read was assuming the games would load. It either doesn't see them or they don't load. I'm not new to emulators, but I'm totally confuzzled...