Unibeast 7.01 Won't Boot

I had been using chameleon enoch to boot my system (HP Compaq dc7800 with Nvidia GeForce 8400 GS) because I was having problems with clover. I couldn't get enoch to work with Sierra, so I decided to try clover again. I made a "legacy boot" USB in Unibeast with inject nvidia on. When I select my USB in BIOS, it says
and then goes to a black screen with a single underscore at the top left. I left it like that for 5 minutes and nothing...

Unibeast 7.01 Won't Boot