3.9 Upgrade broke local installation

I just upgraded to WordPress 3.9 using the upgrade button and its made my index page blank – I’m working on developing a theme on a local installation of wordpress using MAMP. I can use the backend of wordpress and when I create a new post and view it I can see the post but when I try to visit the index its turning up a completely blank page.

Any ideas? Much thanks in advance! – Nick