Cannot login (Internal Server Error)

Just installed OpenFire on a fresh AWS instance. Opened the correct port (5222 for IM and 9090 for admin). I created a user, but when trying to connect from any client (tried miranda and pidjin) I get the following Java Exception in the OpenFire logs:

2016.03.28 22:27:48 INFO [pool-22-thread-4]: org.jivesoftware.openfire.session.LocalOutgoingServerSession[Authenticate local domain: ‘’ to remote domain: ‘’] - Unable to authenticate: Remote domain is not accessible according to our configuration (typical causes: server federation is disabled, or domain is blacklisted).

2016.03.28 22:27:48 WARN [socket_c2s-thread-2]: org.jivesoftware.openfire.nio.ConnectionHandler - Closing connection due to exception in session: (0x00000034: nio socket, server, / => /:5222)

java.lang.NoSuchMethodError: java.util.concurrent.ConcurrentHashMap.keySet()Ljava/util/concurrent/Concurrent HashMap$KeySetView;

What am I missing!?!?!

First one is probably just related to being in Pidgin account config as file proxy. You can delete it there, but it shouldn’t cause login issues anyway.

  1. Openfire 4.0.2 problem