Fatal error: Uncaught Error: Call to undefined function Cornerstone\DesandroMasonry\add_filter() in /home/frassati/public_html/wp-content/plugins/cornerstone/includes/integration/DesandroMasonry/DesandroMasonry.php:115 Stack trace: #0 {main} thrown in /home/frassati/public_html/wp-content/plugins/cornerstone/includes/integration/DesandroMasonry/DesandroMasonry.php on line 115