Ok, it does look like there's broken/invalid database rows in _cbsubs_gateway_accounts. I've patched the error and only gateways with an ID of 1, 2, 7, and 6 are displaying properly. 1 row is completely broken and another isn't displaying at all. Looks like in your database that would be "test" and "Kreditkarte". Are you using either of those? If not I recommend deleting their rows in _cbsubs_gateway_accounts database table then checking if working fine now.