If the following 5 plugins are installed, WordPress will not allow you to edit any pages.
WooCommerce Dynamic Pricing 2.5.3
Gravity Forms 1.8.5
Gravity Forms Polls Add-On 2.0
NextGEN Gallery by Photocrati 2.0.58
It must be the combination of these 5 together to duplicate the issue. Tested on 2 different themes
WordPress version 3.8.1