Good question.
As far as I can tell, there is no error set in the browser's console, so apparently all files are loaded as intended.
Nevertheless, there is no content to your questions. All that is displayed is a blank space, so I guess you are using some data structure which is not getting the actual data.
Are you using AJAX to get access to a distant server ? Or Project files ? Are you sure project files were part of your exported game ?
Have you tried hosting your game as HTML5 anywhere else than in Scirra's arcade ? If so do you encounter the same issue ?
Consider posting your capx for further investigation.