I'm not sure if I've explained my problem correctly. In my case the page is already loaded, and the page has been initiated. A user may then attempt to upload a file after the session has timed out. After the file is attempted to be uploaded to the server is when the problem occurs.
d2013 ( 2013-07-16 16:00:28 +0800 )editExecution doesn't seem to reach my onUpload listener in this situation. As a fix, I've also implemented an onclick listener for this button which does nothing. A user will be redirected to a timeout page when clicking the upload button instead of seeing the cryptic error message.
d2013 ( 2013-07-17 15:14:25 +0800 )edit