Hey @Beat_Schmutz – can you let me know what you’ve tried so far? Have you restarted Roon on the iPad? Have you rebooted the iPad, or the Core?
Are you sure the iPad is running the latest version of Roon and iOS, and has free space available?
Those are things I would check first, so let me know if that helps and the details of your setup, and we can take a look if you’re still having problems.