It was still broken for me with the errant comma removed, but I found an additional errant comma on line 198 of file responsive/core/includes/customizer/settings/class-responsive-footer-layout-customizer.php. Removing the commas in both files fixed the theme for me. This site is hosted by GoDaddy using the CloudLinux “Hardened” PHP version 5.6.40, which cannot be updated by me.
