Ashley
I discovered this problem too on my build... confused the life out of me.
I'm using a Windows 7 machine with IE11. running from the C2 it runs fine, but when exported and uploaded, it freezes. I went into the debugger console and there's nothing wrong there. I changed the browser emulation from EDGE to 10, and it started working.
I'm not sure how to dig through the full programme as it's only the uploaded version with the issue and not the "run layout" version. If you have any pointers on how to track the problem down, I'll go digging. The console is not reporting any errors.
As it stands, this is a major problem. I'll not freak for the moment as I'm sure it will be fixed..
Found some more information...
Creating AppCache with manifest: 'http://XXX.XXX.XXX.XXX/nebula_rebuild/offline.appcache'.
AppCache Fatal Error
WEBGL11135: getContext: Context attribute depth:false is not currently supported
Error loading image 'http://XXX.XXX.XXX.XXX/nebula_rebuild/images/galaxy_enemies-sheet0.png': [object Event]
Error loading image 'http://XXX.XXX.XXX.XXX/nebula_rebuild/images/galaxy_enemies-sheet0.png': "
[object Event]{AT_TARGET: 2, bubbles: false, BUBBLING_PHASE: 3, cancelable: false, cancelBubble: false, CAPTURING_PHASE: 1, constructor: Event {...}, currentTarget: HTMLImageElement {...}, defaultPrevented: false, eventPhase: 2, isTrusted: true, srcElement: HTMLImageElement {...}, target: HTMLImageElement {...}, timeStamp: 1434912294476, type: "error"}
for information, if I go to the image referenced there, it exists.
I hope this makes more sense to you than to me
R