You’ll need to contact Gravity Forms about this – as commercial products aren’t supported on these forums.
I ran into the same issue. To get it to work you need to make sure you have the latest version of Gravity Forms which fixes an issue with the jQuery UI Tabs change in the newest version. Otherwise you’ll have to get down and dirty and change a little bit of code. This post should help you get started:
http://stackoverflow.com/questions/16033490/microsoft-jscript-runtime-error-no-such-method-select-for-tabs-widget-instanc
Edit: Downgraded to WP 3.5.2 and works again.
Downgrading isn’t the solution. Upgrading Gravity Forms is.
WordPress v3.6 introduced a new version of jQuery. Gravity Forms, like all plugins and themes, utilized the version of jQuery that is built into the WordPress core.
This change necessitated updates to Gravity Forms to maintain compatibility. So in order to run WordPress v3.6 and Gravity Forms you must have the latest version of Gravity Forms.
This is why renewing Gravity Forms in order to continue receiving software updates is important. You should ALWAYS run the latest version of WordPress AND the latest version of all WordPress plugins for security and compatibility reasons.
Downgrading the version of WordPress you use in this situation could leave your site vulnerable to any security fixes applied in the WordPress v3.6+ release. Same goes for running old versions of Gravity Forms.
