Unity Webplayer not loading (Works in Editor and Standalone)

I am currently using Unity 5 Beta (v14) and am having problems in exporting to unity webplayer. Everything works perfectly in editor and standalone, but when I export to webplayer, the loading bar either never appears or doesn't finish loading.

The project was fine before (was able to play in webplayer fine) but something happened and I'm not sure what it is, as there are no errors in the editor.

The one thing I was able to do was delete the entire NGUI UI from my scene, and then the scene loaded, but NGUI was there before when it was working, so I can't imagine that it is the actual reason.

If anyone has had this problem, or can point me in a direction to finding what is wrong (I have no errors to look at) I would greatly appreciate it!