Will try to check later. But if you make Chrome break on this crash, you should get some good context. what's happening, which variables are undefined etc. Can you post your findings so far?
I did try setting up breakpoints through Chrome, but didn't get any helpful information. I sent you the video from that also. It basically runs through app.js, and just throws the error after function checkCollapse(event). If I try to step through into the function in app.js, it just goes through setting up the events and any normal configs which takes probably a million clicks to get where I need to be.