is_plugin_active() not defined on active plugin, in the thumbnails.php file
You can try this, it works for me 🙂 // We need plugin.php! require_once( ABSPATH . ‘wp-admin/includes/plugin.php’ ); $plugins = get_plugins(); foreach ($plugins as $key => $value) { if ( $value[‘Name’] == ‘Aest Plugins’ ) { // <– name plugin validate if( is_plugin_active( $key ) ){ echo “plugin {$value[‘Name’]} is active”; }else{ echo “plugin {$value[‘Name’]} … Read more