Fatal error: Uncaught Error: Class 'Concrete\Core\Block\BlockController' not found in /srv/www/c5www/html/updates/concrete5-8.5.1/concrete/blocks/image_slider/controller.php:13 Stack trace: #0 {main} thrown in /srv/www/c5www/html/updates/concrete5-8.5.1/concrete/blocks/image_slider/controller.php on line 13