I loaded a blank Arduino program, and now it's not recognized by mass storage (USB). Is there a way to get the board back? Do I need to buy a special cable? run a certain program?

I have the F767ZI board. It would take a long time to create something from scratch. I've tried searching, but most outside C++ programs draw from a bunch of external libraries.(Additionally, I'm using the IHM02A1 dual motor driver.)