[5.0.0] TypeError: Event::getItemsWithPermission() when called from Event::retrieveEvents with $skipPermissions=true

Hello,

When my application calls Event::retrieveEvents with $skipPermissions=true I get the following Exception:

TypeError: IPS\Content\Item::getItemsWithPermission(): Argument #4 ($permissionKey) must be of type string, null given, called in /home/bn2468/public_html/applications/calendar/sources/Event/Event.php on line 2228 (0)

#0 /home/bn2468/public_html/applications/calendar/sources/Event/Event.php(2228): IPS\Content\Item::getItemsWithPermission(Array, 'event_start_dat...', NULL, NULL, true, 0, NULL, false, false, false, false, NULL, false, true, true, true, false, NULL)

#1 /home/bn2468/public_html/applications/bncal/modules/front/calendars/view.php(575): IPS\calendar\Event::retrieveEvents(Object(IPS\calendar\Date), Object(IPS\calendar\Date), NULL, NULL, true, NULL, NULL, true, NULL, 0, Array)

#2 /home/bn2468/public_html/system/Dispatcher/Controller.php(128): IPS\bncal\modules\front\calendars\view->events()

#3 /home/bn2468/public_html/applications/bncal/modules/front/calendars/view.php(27): IPS\Dispatcher\Controller->execute()

#4 /home/bn2468/public_html/system/Dispatcher/Dispatcher.php(169): IPS\bncal\modules\front\calendars\view->execute()

#5 /home/bn2468/public_html/index.php(16): IPS\Dispatcher->run()

#6 {main}

Note the comment: * @param bool $skipPermissions Skip permission checks (used by REST API to fetch all events which are filtered on later)

So I presume the API is also broken (as well as my application).

Thanks.

John