Slim Application Error

The application could not run because of the following error:
Details

Type: TypeError
Code: 0
Message: count(): Argument #1 ($value) must be of type Countable|array, null given
File: /usr/www/users/cmssta/typemill/system/typemill/Models/Navigation.php
Line: 754
Trace

#0 /usr/www/users/cmssta/typemill/system/typemill/Models/Navigation.php(754): count()
#1 /usr/www/users/cmssta/typemill/system/typemill/Controllers/ControllerWebFrontend.php(116): Typemill\Models\Navigation->getPagingForItem()
#2 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/Handlers/Strategies/RequestResponse.php(38): Typemill\Controllers\ControllerWebFrontend->index()
#3 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/Routing/Route.php(363): Slim\Handlers\Strategies\RequestResponse->__invoke()
#4 /usr/www/users/cmssta/typemill/system/typemill/Middleware/CspHeadersMiddleware.php(30): Slim\Routing\Route->handle()
#5 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\CspHeadersMiddleware->process()
#6 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(73): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#7 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(73): Slim\MiddlewareDispatcher->handle()
#8 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/Routing/Route.php(321): Slim\MiddlewareDispatcher->handle()
#9 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/Routing/RouteRunner.php(74): Slim\Routing\Route->run()
#10 /usr/www/users/cmssta/typemill/plugins/version/VersionMiddleware.php(95): Slim\Routing\RouteRunner->handle()
#11 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(280): Plugins\Version\VersionMiddleware->__invoke()
#12 /usr/www/users/cmssta/typemill/system/typemill/Middleware/CustomHeadersMiddleware.php(24): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#13 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\CustomHeadersMiddleware->process()
#14 /usr/www/users/cmssta/typemill/system/typemill/Middleware/AssetMiddleware.php(38): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#15 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\AssetMiddleware->process()
#16 /usr/www/users/cmssta/typemill/system/typemill/Middleware/ValidationErrorsMiddleware.php(35): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#17 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(280): Typemill\Middleware\ValidationErrorsMiddleware->__invoke()
#18 /usr/www/users/cmssta/typemill/system/typemill/Middleware/SecurityMiddleware.php(140): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#19 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\securityMiddleware->process()
#20 /usr/www/users/cmssta/typemill/system/typemill/Middleware/OldInputMiddleware.php(32): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#21 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(280): Typemill\Middleware\OldInputMiddleware->__invoke()
#22 /usr/www/users/cmssta/typemill/system/vendor/slim/twig-view/src/TwigMiddleware.php(115): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#23 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Slim\Views\TwigMiddleware->process()
#24 /usr/www/users/cmssta/typemill/system/typemill/Middleware/FlashMessages.php(32): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#25 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(280): Typemill\Middleware\FlashMessages->__invoke()
#26 /usr/www/users/cmssta/typemill/system/typemill/Middleware/JsonBodyParser.php(25): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#27 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\JsonBodyParser->process()
#28 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/Middleware/RoutingMiddleware.php(45): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#29 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Slim\Middleware\RoutingMiddleware->process()
#30 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/Middleware/ErrorMiddleware.php(77): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#31 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Slim\Middleware\ErrorMiddleware->process()
#32 /usr/www/users/cmssta/typemill/system/typemill/Middleware/SessionMiddleware.php(58): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#33 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\SessionMiddleware->process()
#34 /usr/www/users/cmssta/typemill/system/typemill/Middleware/RemoveCredentialsMiddleware.php(24): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#35 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Typemill\Middleware\RemoveCredentialsMiddleware->process()
#36 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/MiddlewareDispatcher.php(73): Psr\Http\Server\RequestHandlerInterface@anonymous->handle()
#37 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/App.php(209): Slim\MiddlewareDispatcher->handle()
#38 /usr/www/users/cmssta/typemill/system/vendor/slim/slim/Slim/App.php(193): Slim\App->handle()
#39 /usr/www/users/cmssta/typemill/system/typemill/system.php(441): Slim\App->run()
#40 /usr/www/users/cmssta/typemill/index.php(5): require('/usr/www/users/...')
#41 {main}