Does not work in php5.6

I built a site using Rules Panes in PHP5.3 then I upgraded to PHP5.6 and now I get a white screen when I click the submit button on the pane. I then copied all the files over to a new folder(site with a clean database) and tried setting up a test example that just displays a message when clicked. I still get the error. How do I figure out where the problem is?