I installed WordPress 4.0. Took me a redirect loop problem and I could not see the frontend of the page. I deactivated the plugins and gave me an error when viewing the theme, but at least it looked. I reinstalled the theme and everything looked good, but now the visual text editor is not displayed correctly.
Completely disable all of your plugins, then re-download a new copy of the theme from ThemeForest and overwrite all of your current theme files on your server with a fresh copy and see if that fixes the issue. You won't lose any content or settings since those are stored in the database, but if you have made any changes directly to any of the theme code then you should make a backup of your current theme files so you don't lose your changes.