Next Cloud 20. Protocol shows "NotPermittedException" if i try to open a document with collabora online

NextCloud 20 is installed on a RootServer.

OCP\Files\NotPermittedException:
/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/apps/richdocuments/lib/Controller/WopiController.php - line 361:

OC\Files\Node\File->fopen(“rb”)

/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 169:

OCA\Richdocuments\Controller\WopiController->getFile(“221”, “EnZ4ix0oc6M … Z”)

/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 100:

OC\AppFramework\Http\Dispatcher->executeController(OCA\Richdocu … {}, “getFile”)

/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/lib/private/AppFramework/App.php - line 152:

OC\AppFramework\Http\Dispatcher->dispatch(OCA\Richdocu … {}, “getFile”)

/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/lib/private/Route/Router.php - line 308:

OC\AppFramework\App::main(“OCA\Richdo … r”, “getFile”, OC\AppFramew … {}, { action: nu … "})

/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/lib/base.php - line 1009:

OC\Route\Router->match("/apps/richd … s")

/var/www/vhosts/meinekueche.de/httpdocs/nextcloud/index.php - line 37:

OC::handleRequest()

Is there any idea??

Thommy