WSOD because of namespace collision

Problem/Motivation

The TypeError was caused by namespace collision in the ad module:
- Files: PublishAdContent.php and UnpublishAdContent.php
- Wrong namespace: Drupal\scheduler\Plugin\Action
- Correct namespace: Drupal\ad_content_scheduler\Plugin\Action

WSOD because views_bulk_operations is getting a false value:

Another module gave this error:

TypeError: in_array(): Argument #2 ($haystack) must be of type array, false given in in_array() (line 88 of modules/contrib/views_bulk_operations/src/Service/ViewsBulkOperationsActionManager.php).
Drupal\views_bulk_operations\Service\ViewsBulkOperationsActionManager->findDefinitions() (Line: 129)
Drupal\views_bulk_operations\Service\ViewsBulkOperationsActionManager->getDefinitions() (Line: 139)
Drupal\views_bulk_operations\Plugin\views\field\ViewsBulkOperationsBulkForm->init() (Line: 913)
Drupal\views\Plugin\views\display\DisplayPluginBase->getHandlers() (Line: 1100)
Drupal\views\ViewExecutable->_initHandler() (Line: 958)
Drupal\views\ViewExecutable->initHandlers() (Line: 2337)
Drupal\views\Plugin\views\display\DisplayPluginBase->preExecute() (Line: 1752)
Drupal\views\ViewExecutable->preExecute() (Line: 1687)
Drupal\views\ViewExecutable->executeDisplay() (Line: 81)
Drupal\views\Element\View::preRenderViewElement()
call_user_func_array() (Line: 113)
Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 886)
Drupal\Core\Render\Renderer->doCallback() (Line: 431)
Drupal\Core\Render\Renderer->doRender() (Line: 248)
Drupal\Core\Render\Renderer->render() (Line: 238)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 637)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray()
call_user_func() (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (Line: 186)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 54)
Drupal\simple_oauth\HttpMiddleware\BasicAuthSwap->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: 116)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 90)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 43)
Drupal\webform_product\RedirectMiddleware->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)

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes