Hi, I narrowed the problem down to this file: Fireflight_edit.ogg
In "tutorial level" - event 19, when you play that sound then all requests after it fail (AJAX requests and C2's _reloadpoll_ requests).
This only happens in Chrome and it only happens in preview. It works ok when exported.
I think it's got to do with file size. I tried playing a 10MB ogg file in a new project and got the same problem. Made the file smaller and it works.