S2S Connection failed

I am attempting to add a contact from another domain, and get an error.

I’ve tried every combination of the S2S security settings. The remote server is able to add users on google apps domains and other XMPP servers, but not on my openfire server.

2015.09.11 11:05:35 org.jivesoftware.openfire.server.ServerDialback - ServerDialback: OS - Ignoring unexpected answer in validation from: id: 8f85a520-188f-410d-bb6f-e6014105cbd6 for domain: answer:<stream:features xmlns:stream=“http://etherx.jabber.org/streams”></stream:features>
2015.09.11 11:07:35 org.jivesoftware.openfire.session.LocalOutgoingServerSession - Fail to connect to for