FF6 RAM Editor crashing

I had to disable DEP for it first but now I get "An exception of class OutOfBoundsException was not handled. The application must be shut down."

This is a pretty generic error. I can't really help you because I run the 32 bit version of Windows 7. But given the fact the editor was made in 2005, it is most likely related to the fact you're trying to run it on Windows 7 64 bit.