Fatal error: Uncaught Error: Call to undefined function add_filter() in /home/savsol/public_html/wp-content/plugins/wp-staging/Backend/Optimizer/wp-staging-optimizer.php:112 Stack trace: #0 {main} thrown in /home/savsol/public_html/wp-content/plugins/wp-staging/Backend/Optimizer/wp-staging-optimizer.php on line 112