Recording button was visible early but not showing suddenly

I was able to do the record early. But now the record but not visible after I am receiving the following Jicofo error on my log file. Could any one plz check and let me know the solution.

SEVERE: [28] BaseEventEmitter.wrap#51: Exception from event handler: null
java.lang.IllegalArgumentException
at java.util.concurrent.ScheduledThreadPoolExecutor.scheduleAtFixedRate(ScheduledThreadPoolExecutor.java:565)
at org.jitsi.jicofo.bridge.JvbDoctor.addBridge(JvbDoctor.java:132)
at org.jitsi.jicofo.bridge.BridgeSelector.addJvbAddress(BridgeSelector.java:133)
at org.jitsi.jicofo.bridge.BridgeMucDetector.onInstanceStatusChanged(BridgeMucDetector.kt:49)
at org.jitsi.jicofo.bridge.BridgeMucDetector.onInstanceStatusChanged(BridgeMucDetector.kt:32)
at org.jitsi.jicofo.xmpp.BaseBrewery.processInstanceStatusChanged(BaseBrewery.java:302)
at org.jitsi.jicofo.xmpp.BaseBrewery.processMemberPresence(BaseBrewery.java:276)
at org.jitsi.jicofo.xmpp.BaseBrewery$ChatRoomListenerImpl.memberJoined(BaseBrewery.java:217)
at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.lambda$processOtherPresence$12(ChatRoomImpl.java:834)
at org.jitsi.utils.event.SyncEventEmitter$fireEvent$1$1.invoke(EventEmitter.kt:64)
at org.jitsi.utils.event.SyncEventEmitter$fireEvent$1$1.invoke(EventEmitter.kt:64)
at org.jitsi.utils.event.BaseEventEmitter.wrap(EventEmitter.kt:49)
at org.jitsi.utils.event.SyncEventEmitter.fireEvent(EventEmitter.kt:64)
at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.processOtherPresence(ChatRoomImpl.java:833)
at org.jitsi.impl.protocol.xmpp.ChatRoomImpl.processPresence(ChatRoomImpl.java:887)
at org.jivesoftware.smackx.muc.MultiUserChat$3.processStanza(MultiUserChat.java:294)
at org.jivesoftware.smack.AbstractXMPPConnection.lambda$invokeStanzaCollectorsAndNotifyRecvListeners$8(AbstractXMPPConnection.java:1626)
at org.jivesoftware.smack.AsyncButOrdered$Handler.run(AsyncButOrdered.java:151)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)