I've figured it out!
I am on version 1.4. I'm guessing untill you hover your pointer over a box it has not decided what is in there yet. So when I hover my pointer over a box that should contain a magical item it causes some kind of conflict and crashes. Hopefully this has been fixed in 1.42. Does anyone know if I am right and has it been fixed?
Also is there a place with known issues all in one place that you could check to see if any problems you run into are being sorted out? If not the same things are going to come up over and over on the forum and difficult to find.