Item-not-found(404)

I installed openfire (4.1.1) with ofmeet plugin (0.3.28) to create a video meeting through rocket-chat.

All is working, in rocket-chat i able to start a new video meeting, but sometimes openfire falls in error and in the error.log i see this:

2017.01.30 08:40:03 org.jitsi.jicofo.JitsiMeetConference - net.java.sip.communicator.service.protocol.OperationFailedException: Failed to join the room

net.java.sip.communicator.service.protocol.OperationFailedException: Failed to join the room

at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.joinAs(ChatRoomImpl.java:200)

at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.joinAs(ChatRoomImpl.java:290)

at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.join(ChatRoomImpl.java:249)

at org.jitsi.jicofo.JitsiMeetConference.joinTheRoom(JitsiMeetConference.java:342)

at org.jitsi.jicofo.JitsiMeetConference.maybeJoinTheRoom(JitsiMeetConference.java: 324)

at org.jitsi.jicofo.JitsiMeetConference.registrationStateChanged(JitsiMeetConferen ce.java:1119)

at org.jitsi.jicofo.ProtocolProviderHandler.registrationStateChanged(ProtocolProvi derHandler.java:123)

at net.java.sip.communicator.service.protocol.AbstractProtocolProviderService.fire RegistrationStateChanged(AbstractProtocolProviderService.java:176)

at net.java.sip.communicator.service.protocol.AbstractProtocolProviderService.fire RegistrationStateChanged(AbstractProtocolProviderService.java:130)

at org.jitsi.impl.protocol.xmpp.XmppProtocolProvider.register(XmppProtocolProvider .java:171)

at org.jitsi.jicofo.util.RegisterThread.run(RegisterThread.java:38)

Caused by: item-not-found(404)

at org.jivesoftware.smackx.muc.MultiUserChat.create(MultiUserChat.java:360)

at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.joinAs(ChatRoomImpl.java:152)

… 10 more

2017.01.30 08:40:03 org.jitsi.impl.protocol.xmpp.OperationSetJingleImpl - Received an error: code=404 message=null

2017.01.30 08:40:03 org.jitsi.impl.protocol.xmpp.OperationSetJingleImpl - Received an error: code=404 message=null

2017.01.30 08:40:03 net.java.sip.communicator.util.UtilActivator - An uncaught exception occurred in thread=Thread[Thread-156,5,main] and message was: null

java.lang.NullPointerException

at org.jitsi.impl.protocol.xmpp.XmppProtocolProvider.register(XmppProtocolProvider .java:178)

at org.jitsi.jicofo.util.RegisterThread.run(RegisterThread.java:38)

Is there a fix or a specific setting to avoid this random error (It happened in a week due Times)?

Thanks.

Gigi