The "entity_form_display" entity type did not specify a "edit" form class

I am running into this issue as well, only both Drupal 10.2 and 10.3. I thought originally, it was only happening when I was changing field widget configurations, but now I can reproduce it by simply going to the form display and re-saving the form/page without making any changes.

I will say we are using Inline Entity Form, which is how I ended up at this thread.

Also, seeing the note in the thread about someone was using the Entity Form Mode module, I am also pointing out that we do also use the Form Mode Manager module. It sounds like it may be a similar module, possibly doing similar things.

Error and stack trace:

The website encountered an unexpected error. Try again later.

Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException: The "entity_form_display" entity type did not specify a "edit" form class. in Drupal\Core\Entity\EntityTypeManager->getFormObject() (line 212 of core/lib/Drupal/Core/Entity/EntityTypeManager.php).
Drupal\Core\Entity\HtmlEntityFormController->getFormObject(Object, 'entity_form_display.edit.default') (Line: 58)
Drupal\Core\Controller\FormController->getContentResult(Object, Object) (Line: 39)
Drupal\layout_builder\Controller\LayoutBuilderHtmlEntityFormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 638)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 121)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 53)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->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: 86)
Drupal\alert_message\StackMiddleware\AlertMessage->handle(Object, 1, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 741)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)