Error after save elements without created element

Hi,
I create a new webform from the administration then I click Save elements without having created an element, I come across an error :
The website encountered an unexpected error. Please try again later.
Recoverable fatal error: Argument 3 passed to Drupal\webform_ui\WebformUiEntityForm::buildUpdatedElementsRecursive() must be of the type array, string given, called in /var/www/drupal/modules/webform/modules/webform_ui/src/WebformUiEntityForm.php on line 343 and defined in Drupal\webform_ui\WebformUiEntityForm->buildUpdatedElementsRecursive() (line 376 of modules/webform/modules/webform_ui/src/WebformUiEntityForm.php).

Drupal\webform_ui\WebformUiEntityForm->buildUpdatedElementsRecursive(Array, '', '', Array) (Line: 343)
Drupal\webform_ui\WebformUiEntityForm->validateForm(Array, Object)
call_user_func_array(Array, Array) (Line: 83)
Drupal\Core\Form\FormValidator->executeValidateHandlers(Array, Object) (Line: 270)
Drupal\Core\Form\FormValidator->doValidateForm(Array, Object, 'webform_form') (Line: 119)
Drupal\Core\Form\FormValidator->validateForm('webform_form', Array, Object) (Line: 571)
Drupal\Core\Form\FormBuilder->processForm('webform_form', Array, Object) (Line: 314)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 74)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 574)
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}()
call_user_func_array(Object, Array) (Line: 139)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 62)
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: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 652)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)