Fatal error: Uncaught Error: Call to undefined function add_action() in /home/k1818436/public_html/wp-content/plugins/pdf-viewer-for-wordpress/admin/tnc-pdf-viewer-options.php:2 Stack trace: #0 /home/k1818436/public_html/wp-content/plugins/pdf-viewer-for-wordpress/pdf-viewer-for-wordpress.php(15): include() #1 {main} thrown in /home/k1818436/public_html/wp-content/plugins/pdf-viewer-for-wordpress/admin/tnc-pdf-viewer-options.php on line 2