Fatal error: Uncaught Functional\Exceptions\InvalidArgumentException: Functional\flatten() expects parameter 1 to be array or instance of Traversable, integer given in /customers/3/2/6/amocs.de/httpd.www/includes/vendor/lstrojny/functional-php/src/Functional/Exceptions/InvalidArgumentException.php:271 Stack trace: #0 /customers/3/2/6/amocs.de/httpd.www/includes/vendor/lstrojny/functional-php/src/Functional/Exceptions/InvalidArgumentException.php(69): Functional\Exceptions\InvalidArgumentException::assertCollectionAlike(0, 'Traversable', 'Functional\\flat...', 1) #1 /customers/3/2/6/amocs.de/httpd.www/includes/vendor/lstrojny/functional-php/src/Functional/Flatten.php(25): Functional\Exceptions\InvalidArgumentException::assertCollection(0, 'Functional\\flat...', 1) #2 /customers/3/2/6/amocs.de/httpd.www/includes/src/News/Category.php(300): Functional\flatten(0) #3 /customers/3/2/6/amocs.de/httpd.www/includes/src/News/Controller.php(214): JTL\News\Category->getOverview(Object(stdClass)) #4 /customers/3/2/6/amocs.de/httpd.www/news.php(81): JTL\News\Controller->displayOverview(Object(JTL\Pagination\Pagination), 0, 0, 1) #5 /customers/3/2/6/amocs.de/httpd.www/index.php(13): require('/customers/3/2/...') #6 {main} thrown in /customers/3/2/6/amocs.de/httpd.www/includes/vendor/lstrojny/functional-php/src/Functional/Exceptions/InvalidArgumentException.php on line 271