Fatal error: Uncaught TypeError: Return value of Project\Module\Reise\Reise::getLeistung() must be an instance of Project\Module\Leistung\Leistung, null returned in /www/htdocs/v155389/go-and-fly/preview/src/Module/Reise/Reise.php:184 Stack trace: #0 /www/htdocs/v155389/go-and-fly/preview/vendor/twig/twig/lib/Twig/Extension/Core.php(1595): Project\Module\Reise\Reise->getLeistung() #1 /www/htdocs/v155389/go-and-fly/preview/vendor/twig/twig/lib/Twig/Environment.php(373) : eval()'d code(318): twig_get_attribute(Object(Twig_Environment), Object(Twig_Source), Object(Project\Module\Reise\Reise), 'getLeistung', Array) #2 /www/htdocs/v155389/go-and-fly/preview/vendor/twig/twig/lib/Twig/Template.php(389): __TwigTemplate_700c745f481ae8b665ea741bb3e3c89d5d0fd24056542ca8244bcaae9179be63->doDisplay(Array, Array) #3 /www/htdocs/v155389/go-and-fly/preview/vendor/twig/twig/lib/Twig/Template.php(366): Twig_Template->displayWithErrorHandling(Array, Array) #4 /www/htdocs/v155389/go-and-fly/preview/vendor/twig/twig/lib/Twig/Environment.php(3 in /www/htdocs/v155389/go-and-fly/preview/src/Module/Reise/Reise.php on line 184