Problem
When attempting to use $menuLinkContent->access('randomoperation') an exception is thrown.
The website encountered an unexpected error. Please try again later.
TypeError: Argument 1 passed to Drupal\Core\Access\AccessResult::orIf() must implement interface Drupal\Core\Access\AccessResultInterface, null given, called in /core/lib/Drupal/Core/Entity/EntityAccessControlHandler.php on line 106 in Drupal\Core\Access\AccessResult->orIf() (line 314 of core/lib/Drupal/Core/Access/AccessResult.php).
Drupal\Core\Access\AccessResult->orIf(NULL) (Line: 106)
Drupal\Core\Entity\EntityAccessControlHandler->access(Object, 'clone', Object, ) (Line: 708)
Drupal\Core\Entity\ContentEntityBase->access('clone') (Line: 32)
Cause
\Drupal\menu_link_content\MenuLinkContentAccessControlHandler::checkAccess must always return an object implementing \Drupal\Core\Access\AccessResultInterface. However it incorrectly returns NULL when an access to an operation other than 'view', 'update', or 'delete' is requested.
Motivation
Entity Clone automatically adds a 'Clone' local task to content entities. Patch #2743379: Clone operation shows regardless of permission for Entity Clone updates its clone route to use a 'clone' operation. However because Menu Link Content mishandles unrecognised operations, the menu link page edit form throws an exception.