I upgraded my site to WordPress 3.5 from the previous version, I think 3.4 or something. The files updated, however when I go to log into the admin it says I need to upgrade the database. I click to upgrade the database and it just hangs. I've tried uploading files manually, renaming plugins folder, renaming theme so twentytwelve is active and it still didn't do anything. It just works for a little then goes to a blank screen.
I need to fix this problem and have the website back to normal with the current theme and plugins.