FF6Tools - Browser-Based ROM Editor

So, I just went a blew the dust off my old Mac to see if I could get this to work. The answer is no.

After clicking on the binary to open it, nothing happens. It appears on the dashboard and when I click the icon the bar at the top gives me:

FFG Tools, File, Edit, View, Window, Help

I tried going to File-Open thinking I must need to give it a ROM file, but when I open up the directory with the ROM, it's all grayed out and doesn't except it. I've tried dragging and dropping the ROM onto the executable too and got "The document "FFIII.smc" could not be opened. FF6 Tools cannot open files in the document format."

My OS is 10.11.5

Not sure what could be going on. Is there some additional library I need to go downloading? This machine I'm using is pretty ancient, but it's my only Mac.