Exception: Serialization of 'Closure' is not allowed in serialize()

Problem/Motivation

Unable to access configuration screen with this error dispalyed

The website encountered an unexpected error. Please try again later.

Exception: Serialization of 'Closure' is not allowed in serialize() (line 152 of core\lib\Drupal\Component\Annotation\Plugin\Discovery\AnnotatedClassDiscovery.php).
Drupal\Component\Annotation\Plugin\Discovery\AnnotatedClassDiscovery->getDefinitions() (Line: 86)
Drupal\Component\Plugin\Discovery\DerivativeDiscoveryDecorator->getDefinitions() (Line: 214)
Drupal\markdown\PluginManager\InstallablePluginManager->findDefinitions() (Line: 175)
Drupal\Core\Plugin\DefaultPluginManager->getDefinitions() (Line: 385)
Drupal\markdown\PluginManager\InstallablePluginManager->getRuntimeDefinitions() (Line: 352)
Drupal\markdown\PluginManager\InstallablePluginManager->getDefinitions() (Line: 448)
Drupal\markdown\PluginManager\InstallablePluginManager->installedDefinitions() (Line: 441)
Drupal\markdown\PluginManager\InstallablePluginManager->installed() (Line: 86)
Drupal\markdown\PluginManager\ParserManager->getDefaultParser() (Line: 106)
Drupal\markdown\Form\OverviewForm->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 532)
Drupal\Core\Form\FormBuilder->retrieveForm('markdown_overview', Object) (Line: 278)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 91)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 573)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 151)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 49)
Drupal\remove_http_headers\StackMiddleware\RemoveHttpHeadersMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 708)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Steps to reproduce

Drupal 8.9.20
composer require drupal/markdown:3.0-rc1
composer require league/commonmark

Visit markdown text format configuration (eg. /admin/config/content/markdown) after upgrading from "version": "1.3" to "version": "3.0.0-rc1"

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes