Incompatibility with page_manager?
>>> [!note] Migrated issue
<!-- Drupal.org comment -->
<!-- Migrated from issue #2958186. -->
Reported by: [anybody](https://www.drupal.org/user/291091)
>>>
<p>When I enabled menu entity index I got this error / WSOD. The module is not working for me. Perhaps an incompatibility with page_manager?</p>
<p>Backtrace:</p>
<blockquote><p>The website encountered an unexpected error. Please try again later.<br>
LogicException: The database connection is not serializable. This probably means you are serializing an object that has an indirect reference to the database connection. Adjust your code so that is not necessary. Alternatively, look at DependencySerializationTrait as a temporary solution. in Drupal\Core\Database\Connection->__sleep() (line 1472 of core/lib/Drupal/Core/Database/Connection.php).</p>
<p>Drupal\Core\Database\Connection->__sleep()<br>
serialize(Array) (Line: 240)<br>
Drupal\Core\Cache\DatabaseBackend->doSetMultiple(Array) (Line: 193)<br>
Drupal\Core\Cache\DatabaseBackend->setMultiple(Array) (Line: 181)<br>
Drupal\Core\Cache\DatabaseBackend->set('entity_type', Array, -1, Array) (Line: 71)<br>
Drupal\Core\Plugin\DefaultPluginManager->cacheSet('entity_type', Array, -1, Array) (Line: 220)<br>
Drupal\Core\Plugin\DefaultPluginManager->setCachedDefinitions(Array) (Line: 176)<br>
Drupal\Core\Plugin\DefaultPluginManager->getDefinitions() (Line: 22)<br>
Drupal\Core\Plugin\DefaultPluginManager->getDefinition('page_variant', ) (Line: 126)<br>
Drupal\Core\Entity\EntityTypeManager->getDefinition('page_variant') (Line: 233)<br>
Drupal\Core\Entity\EntityTypeManager->getHandler('page_variant', 'storage') (Line: 169)<br>
Drupal\Core\Entity\EntityTypeManager->getStorage('page_variant') (Line: 65)<br>
Drupal\page_manager\Routing\VariantRouteFilter->__construct(Object, Object, Object) (Line: 270)<br>
Drupal\Component\DependencyInjection\Container->createService(Array, 'page_manager.variant_route_filter') (Line: 171)<br>
Drupal\Component\DependencyInjection\Container->get('page_manager.variant_route_filter', 1) (Line: 480)<br>
Drupal\Component\DependencyInjection\Container->resolveServicesAndParameters(Array) (Line: 319)<br>
Drupal\Component\DependencyInjection\Container->createService(Array, 'router.no_access_checks') (Line: 171)<br>
Drupal\Component\DependencyInjection\Container->get('router.no_access_checks', 1) (Line: 480)<br>
Drupal\Component\DependencyInjection\Container->resolveServicesAndParameters(Array) (Line: 230)<br>
Drupal\Component\DependencyInjection\Container->createService(Array, 'exception.custom_page_html') (Line: 171)<br>
Drupal\Component\DependencyInjection\Container->get('exception.custom_page_html') (Line: 105)<br>
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.exception', Object) (Line: 228)<br>
Symfony\Component\HttpKernel\HttpKernel->handleException(Object, Object, 1) (Line: 79)<br>
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)<br>
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)<br>
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)<br>
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)<br>
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 50)<br>
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 47)<br>
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)<br>
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)<br>
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 664)<br>
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)
</p></blockquote>
issue