I installed Gravity Forms on a site and created 3 forms. I tested them out about a week ago and they worked fine. Now when I fill any of the forms and click submit, it just refreshes the page. The notifications I set up don't get emailed, and there is no text confirming the submission. Also, there is no submission entry in the backend of WP.
I've installed Gravity Forms on a ton of sites and I've never had this issue before. The only other plugin active is Option Tree, and it was active when the form was working last week.
Here's one of the forms: http://www.projecthopeco.com/contact-us/