Unexpected Error

When I am prompted with the locker screen and enter a password I am get the following:

The website encountered an unexpected error. Please try again later.
Error: Call to undefined method Symfony\Component\HttpFoundation\Session\Flash\FlashBag::clean() in Drupal\locker\EventSubscriber\LockerSubscriber->checkForRedirection() (line 29 of modules/contrib/locker/src/EventSubscriber/LockerSubscriber.php).

Drupal\locker\EventSubscriber\LockerSubscriber->checkForRedirection(Object, 'kernel.request', Object)
call_user_func(Array, Object, 'kernel.request', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.request', Object) (Line: 127)
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: 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: 664)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)