Fatal error: Uncaught Error: Class 'ContaoBootstrap\Panel\Components\ContentElement\AbstractPanelStartElement' not found in /home/eberhardschwarze/public_html/vendor/contao-bootstrap/panel/src/Components/ContentElement/PanelSingleElement.php:35 Stack trace: #0 {main} thrown in /home/eberhardschwarze/public_html/vendor/contao-bootstrap/panel/src/Components/ContentElement/PanelSingleElement.php on line 35