Fatal error: Uncaught ErrorException: Creation of dynamic property Sabre\CalDAV\Principal\Collection::$principalPrefix is deprecated in /home/udo/daten/syncfoo/lib/Sabre/DAVACL/AbstractPrincipalCollection.php:56 Stack trace: #0 /home/udo/daten/syncfoo/lib/Sabre/DAVACL/AbstractPrincipalCollection.php(56): exception_error_handler(8192, 'Creation of dyn...', '/home/udo/daten...', 56) #1 /home/udo/daten/syncfoo/index.php(29): Sabre\DAVACL\AbstractPrincipalCollection->__construct(Object(Sabre\DAVACL\PrincipalBackend\PDO)) #2 {main} thrown in /home/udo/daten/syncfoo/lib/Sabre/DAVACL/AbstractPrincipalCollection.php on line 56