Fatal error: Uncaught Error: Interface 'Twig_ExtensionInterface' not found in /home/sven/www/svenk.org/~koeppel/src/lib/Twig/Extension.php:11 Stack trace: #0 {main} thrown in /home/sven/www/svenk.org/~koeppel/src/lib/Twig/Extension.php on line 11