Exception in thread "pool-8-thread-2" java.lang.AbstractMethodError

Hello!

After upgrade from 3.4.1 to 3.5.2 I see lots of these messages in the OpenFire window.

JwChat is used as a client.

Exception in thread “pool-8-thread-2” java.lang.AbstractMethodError
at org.jivesoftware.openfire.event.SessionEventDispatcher.dispatchEvent(SessionEve ntDispatcher.java:79)
at org.jivesoftware.openfire.handler.IQAuthHandler.handleIQ(IQAuthHandler.java:176 )
at org.jivesoftware.openfire.handler.IQHandler.process(IQHandler.java:49)
at org.jivesoftware.openfire.IQRouter.handle(IQRouter.java:349)
at org.jivesoftware.openfire.IQRouter.route(IQRouter.java:101)
at org.jivesoftware.openfire.spi.PacketRouterImpl.route(PacketRouterImpl.java:68)
at org.jivesoftware.openfire.SessionPacketRouter.route(SessionPacketRouter.java:10 0)
at org.jivesoftware.openfire.SessionPacketRouter.route(SessionPacketRouter.java:61 )
at org.jivesoftware.openfire.http.HttpSession.sendPendingPackets(HttpSession.java: 460)
at org.jivesoftware.openfire.http.HttpSessionManager$HttpPacketSender.run(HttpSess ionManager.java:318)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

The message appears in the OpenFire window (not in log files) each time a user logins to the server.

The problem was in the User-Status plugin.

The messages stopped to appear after it was disabled

This error is thrown when an application tries to call an abstract method without actual implementation. Abstract methods have no body and cannot be executed. This error can only occur at run time if the definition of some class has incompatibly changed since the currently executing method was last compiled. It usually happens after some library is upgraded while some is not. The dependencies are missing somehow. This means that you are using an old java version of an interface implementation which is missing a new interface method. For example java.sql.Connection interface got a new getSchema method in 1.7. If you have 1.6 JDBC driver and call Connection.getSchema you will get AbstractMethodError. So, make sure you have the latest jar file in your class path not a older copy.