If you want to get back the original version, that is easy to do. Here is a thread with instructions.
The “Submit Assignment” button should be in the upper right corner of the notebook browser window:
But note that button is the very last thing that gets rendered when the browser displays the notebook. From some of your issues with uploads (on the DM thread), it sounds like you may have problems with your internet connection either being very slow or perhaps having some firewall restrictions that might be blocking some items. Or perhaps your browser is missing some plugins.