There's been bugs like this before. My suggestion is to try editing shortcuts on a different map. Like if you're crashing when you try in The Plaza, head out to the magic shop and try it again there. When I was having problems like this a few versions back, I was usually able to find certain map locations that didn't crash me whenever I tried to edit.
If that doesn't work, I am 99.8% certain than there was a work around where you could edit your shortcuts from somewhere in your PS game files and 99.7% sure that how to do that was posted on the forums somewhere.