Error: Call to a member function getType() on null

Problem/Motivation

I would like to upgrade Role Watchdog to compatible version for Drupal 9.

Steps to reproduce

I made an update from a dev-version from June 2020 and get the following error:

Location: http://myproject.test/user/role-history

Error: Call to a member function getType() on null in Drupal\views\Plugin\views\field\EntityField->defineOptions() (line 382 of /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/field/EntityField.php)
#0 /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/PluginBase.php(139): Drupal\views\Plugin\views\field\EntityField->defineOptions()
#1 /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/HandlerBase.php(102): Drupal\views\Plugin\views\PluginBase->init(Object(Drupal\views\ViewExecutable), Object(Drupal\views\Plugin\views\display\Page), Array)
#2 /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/field/FieldPluginBase.php(117): Drupal\views\Plugin\views\HandlerBase->init(Object(Drupal\views\ViewExecutable), Object(Drupal\views\Plugin\views\display\Page), Array)
#3 /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/field/EntityField.php(210): Drupal\views\Plugin\views\field\FieldPluginBase->init(Object(Drupal\views\ViewExecutable), Object(Drupal\views\Plugin\views\display\Page), Array)
#4 /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php(895): Drupal\views\Plugin\views\field\EntityField->init(Object(Drupal\views\ViewExecutable), Object(Drupal\views\Plugin\views\display\Page), Array)
#5 /var/www/myprojectvm/docroot/core/modules/views/src/ViewExecutable.php(1040): Drupal\views\Plugin\views\display\DisplayPluginBase->getHandlers('field')
#6 /var/www/myprojectvm/docroot/core/modules/views/src/ViewExecutable.php(898): Drupal\views\ViewExecutable->_initHandler('field', Array)
#7 /var/www/myprojectvm/docroot/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php(2335): Drupal\views\ViewExecutable->initHandlers()
#8 /var/www/myprojectvm/docroot/core/modules/views/src/ViewExecutable.php(1692): Drupal\views\Plugin\views\display\DisplayPluginBase->preExecute()
#9 /var/www/myprojectvm/docroot/core/modules/views/src/ViewExecutable.php(1627): Drupal\views\ViewExecutable->preExecute(Array)
#10 /var/www/myprojectvm/docroot/core/modules/views/src/Element/View.php(77): Drupal\views\ViewExecutable->executeDisplay('page_2', Array)
#11 [internal function]: Drupal\views\Element\View::preRenderViewElement(Array)
#12 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(100): call_user_func_array(Array, Array)
#13 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/Renderer.php(781): Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_ren...', 'silenced_deprec...', 'Drupal\\Core\\Ren...')
#14 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/Renderer.php(372): Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array)
#15 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/Renderer.php(200): Drupal\Core\Render\Renderer->doRender(Array, false)
#16 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(226): Drupal\Core\Render\Renderer->render(Array, false)
#17 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/Renderer.php(573): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#18 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(227): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#19 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(117): Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#20 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#21 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object(Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#22 /var/www/myprojectvm/docroot/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#23 /var/www/myprojectvm/vendor/symfony/http-kernel/HttpKernel.php(156): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.view', Object(Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent))
#24 /var/www/myprojectvm/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#25 /var/www/myprojectvm/docroot/modules/contrib/simple_oauth/src/HttpMiddleware/BasicAuthSwap.php(67): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#26 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/StackMiddleware/Session.php(57): Drupal\simple_oauth\HttpMiddleware\BasicAuthSwap->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#27 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(47): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#28 /var/www/myprojectvm/docroot/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#29 /var/www/myprojectvm/docroot/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#30 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(47): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#31 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(52): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#32 /var/www/myprojectvm/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#33 /var/www/myprojectvm/docroot/core/lib/Drupal/Core/DrupalKernel.php(708): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#34 /var/www/myprojectvm/docroot/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#35 {main}