Fatal error: Uncaught Functional\Exceptions\InvalidArgumentException: Functional\flatten() expects parameter 1 to be array or instance of Traversable, integer given in /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/lstrojny/functional-php/src/Functional/Exceptions/InvalidArgumentException.php:272 Stack trace: #0 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/lstrojny/functional-php/src/Functional/Exceptions/InvalidArgumentException.php(70): Functional\Exceptions\InvalidArgumentException::assertCollectionAlike() #1 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/lstrojny/functional-php/src/Functional/Flatten.php(26): Functional\Exceptions\InvalidArgumentException::assertCollection() #2 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Link/LinkGroup.php(136): Functional\flatten() #3 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Link/LinkGroupList.php(200): JTL\Link\LinkGroup->map() #4 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Link/LinkGroupList.php(92): JTL\Link\LinkGroupList->loadDefaultGroups() #5 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Services/JTL/LinkService.php(97): JTL\Link\LinkGroupList->loadAll() #6 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Services/JTL/LinkService.php(51): JTL\Services\JTL\LinkService->initLinkGroups() #7 [internal function]: JTL\Services\JTL\LinkService->__construct() #8 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/illuminate/container/Container.php(877): ReflectionClass->newInstanceArgs() #9 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/illuminate/container/Container.php(714): Illuminate\Container\Container->build() #10 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/illuminate/container/Container.php(284): Illuminate\Container\Container->resolve() #11 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/illuminate/container/Container.php(829): Illuminate\Container\Container->Illuminate\Container\{closure}() #12 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/illuminate/container/Container.php(714): Illuminate\Container\Container->build() #13 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/illuminate/container/Container.php(661): Illuminate\Container\Container->resolve() #14 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Services/Container.php(101): Illuminate\Container\Container->get() #15 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Session/Frontend.php(274): JTL\Services\Container->getLinkService() #16 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Session/Frontend.php(91): JTL\Session\Frontend->updateGlobals() #17 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Session/Frontend.php(63): JTL\Session\Frontend->setStandardSessionVars() #18 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/src/Session/Frontend.php(49): JTL\Session\Frontend->__construct() #19 /var/www/vhosts/pro-schlafen.de/httpdocs/includes/globalinclude.php(119): JTL\Session\Frontend::getInstance() #20 /var/www/vhosts/pro-schlafen.de/httpdocs/index.php(6): require('...') #21 {main} thrown in /var/www/vhosts/pro-schlafen.de/httpdocs/includes/vendor/lstrojny/functional-php/src/Functional/Exceptions/InvalidArgumentException.php on line 272