Removing the qa-page.js means no AJAX operations will works and it will load a whole new page for everything, even voting.
To debug the issue, the best way is to use Chrome:
1. Open Chrome Dev Tools
2. Go to the network tab.
3. Tick "Preserve log" at the top, and also in the Console at the bottom.
4. Do an action on the site, for example voting. A new "request" should appear in the list.
5. Check if there are any errors in the console.
6. If the request there is in red there was a server error, it should say what that is.
7. Otherwise, click the item in the list then look at the Response tab on the right hand side, under normal circumstances it should say QA_AJAX_RESPONSE plus some numbers or other data.