Error: Call to undefined method Drupal\feeds\State::messenger()

Additional Stacktrace

Drupal\feeds\FeedViewBuilder->getBuildDefaults() (Line: 157)
Drupal\Core\Entity\EntityViewBuilder->viewMultiple() (Line: 123)
Drupal\Core\Entity\EntityViewBuilder->view() (Line: 134)
Drupal\Core\Entity\Controller\EntityViewController->view()
call_user_func_array() (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 638)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 121)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741)
Drupal\Core\DrupalKernel->handle() (Line: 19)

Thanks for the fast reply. No, I don't have any patches for the feeds module applied.

I checked a different test system and there I actually get the error you mention (Error: Call to a member function addMessage() on null in Drupal\feeds\State->displayMessages()) during the cron runs. So it seems to actually be two different errors depending on whether the feed content page is accessed (i.e. /feed/8) or the cron jobs are executed.

What I wondered though ... the messenger is addressed different ways in the feed module. No clue if that has to do something at all though.

$this->messenger()

/src/Controller/CustomSourceListController.php:130:        $this->messenger()->addError($e->getMessage());
./src/FeedTypeForm.php:355:    $this->messenger()->addStatus($this->t('Your changes have been saved.'));
./src/Feeds/Processor/EntityProcessorBase.php:1292:          $this->messenger()->addWarning($this->t('When mapping to the entity ID (@name), it is recommended to set it as unique.', [
./src/FeedForm.php:225:      $this->messenger()->addMessage($this->t('%title has been created.', $t_args));
./src/FeedForm.php:229:      $this->messenger()->addMessage($this->t('%title has been updated.', $t_args));
./src/FeedForm.php:235:      $this->messenger()->addError($this->t('The feed could not be saved.'));
./src/Form/CustomSourceEditForm.php:137:    $this->messenger()->addStatus($this->t('The source %label has been updated on the feed type %feed_type.', [
./src/Form/MappingForm.php:161:          $this->messenger()->addWarning($this->t('Your changes will not be saved until you click the <em>Save</em> button at the bottom of the page.'));
./src/Form/MappingForm.php:392:      $this->messenger()->addWarning($e->getMessage());
./src/Form/MappingForm.php:1076:    !empty($message) ? $this->messenger()->addWarning(Markup::create(implode('<br />', $message))) : TRUE;
./src/Form/DeleteMultipleForm.php:53:      $this->messenger()->addMessage($this->formatPlural($count, 'Deleted 1 feed.', 'Deleted @count feeds.'));
./src/Form/FeedUnlockForm.php:45:    $this->messenger()->addMessage($this->t('%title has been unlocked.', $args));
./src/Form/FeedDeleteForm.php:73:    $this->messenger()->addMessage($this->t('%title has been deleted.', $args));
./src/Form/ClearMultipleForm.php:52:      $this->messenger()->addMessage($this->formatPlural($count, 'Deleted items of 1 feed.', 'Deleted items of @count feeds.'));
./src/Form/ImportMultipleForm.php:52:      $this->messenger()->addMessage($this->formatPlural($count, 'Imported 1 feed.', 'Imported @count feeds.'));
./src/Form/FeedScheduleImportForm.php:61:    $this->messenger()->addStatus($this->t('%title has been scheduled for import.', $args));
./src/Form/CustomSourceDeleteForm.php:100:    $this->messenger()->addStatus($this->t('The source %label has been deleted from the feed type %feed_type.', [
./src/FeedExpireHandler.php:26:      $this->messenger()->addWarning($this->t('The feed became locked before the expiring could begin.'));
./src/FeedExpireHandler.php:83:      $this->messenger()->addError($e->getMessage());
./src/FeedExpireHandler.php:105:      $this->messenger()->addStatus($this->t('Expired @count items.', ['@count' => $state->total]));
./src/Plugin/Type/Target/TargetBase.php:113:    return $this->messenger();
./modules/log/src/Form/DeleteForm.php:44:    $this->messenger()->addMessage($this->t('Log %id has been deleted.', [
./modules/log/src/Form/ClearLogConfirmForm.php:47:    $this->messenger()->addStatus($this->t('Logs cleared for feed %label.', [

against \Drupal::messenger()

./feeds.install:49:  $messenger = \Drupal::messenger();
./tests/src/Kernel/FeedsEventsTest.php:63:    $messages = \Drupal::messenger()->all();
./tests/src/Kernel/FeedsEventsTest.php:68:    \Drupal::messenger()->deleteAll();
./tests/src/Kernel/FeedsEventsTest.php:92:    $messages = \Drupal::messenger()->all();
./tests/src/Kernel/EntityIdTest.php:52:    $messages = \Drupal::messenger()->all();
./tests/src/Kernel/EntityIdTest.php:165:    $messages = \Drupal::messenger()->all();
./tests/src/Kernel/Feeds/Processor/GenericContentEntityProcessorTest.php:106:    $messages = \Drupal::messenger()->all();
./tests/src/Kernel/Feeds/Target/LinkTest.php:83:    $messages = \Drupal::messenger()->messagesByType('warning');
./tests/src/Kernel/Feeds/Target/TimestampTest.php:105:    $messages = \Drupal::messenger()->messagesByType('warning');
./tests/src/Kernel/Feeds/Target/BookTest.php:297:    $messages = \Drupal::messenger()->all();
./tests/src/Traits/FeedsCommonTrait.php:351:    $messages = \Drupal::messenger()->all();

I've added the changes in State.php to a system that had the messages appear every 5 minutes in watchdog - and the messages don't appear anymore