Fatal error: Uncaught Error: Call to undefined function is_plugin_active() in /www/wp-content/plugins/photo-gallery/photo-gallery.php:2497 Stack trace: #0 /www/wp-settings.php(342): include_once() #1 /www/wp-config.php(90): require_once('/www/wp-setting...') #2 /www/wp-load.php(37): require_once('/www/wp-config....') #3 /www/wp-blog-header.php(13): require_once('/www/wp-load.ph...') #4 /www/index.php(17): require('/www/wp-blog-he...') #5 {main} thrown in /www/wp-content/plugins/photo-gallery/photo-gallery.php on line 2497