javax.security.sasl.SaslException: ELY05053: Callback handler failed for unknown reason [Caused by java.lang.NullPointerException]
        at org.wildfly.security.sasl.util.AbstractSaslParticipant.tryHandleCallbacks(AbstractSaslParticipant.java:124)
        at org.wildfly.security.sasl.entity.EntitySaslClient.evaluateMessage(EntitySaslClient.java:168)
        at org.wildfly.security.sasl.util.AbstractSaslParticipant.evaluateMessage(AbstractSaslParticipant.java:199)
        at org.wildfly.security.sasl.util.AbstractSaslClient.evaluateChallenge(AbstractSaslClient.java:79)
        at org.wildfly.security.sasl.entity.EntityTest.testClientNotTrustedByServer(EntityTest.java:504)
Caused by: java.lang.NullPointerException
        at java.base/java.util.ArrayList.<init>(ArrayList.java:178)
        at org.wildfly.security.auth.client.AuthenticationConfiguration$ClientCallbackHandler.handle(AuthenticationConfiguration.java:1744)
        at org.wildfly.security.sasl.util.AbstractSaslParticipant.tryHandleCallbacks(AbstractSaslParticipant.java:120)
        ... 4 more

openjdk version "9"
OpenJDK Runtime Environment (build 9+181)
OpenJDK 64-Bit Server VM (build 9+181, mixed mode)