Recordings is not works properly

Go to the room and start recording, then stop recording and start again. The next error shows in java console:
java.lang.IllegalThreadStateException: null
at java.lang.Thread.start(Unknown Source)
at org.apache.openmeetings.screenshare.Core.resultReceived(Core.java:563)
at org.red5.client.net.rtmp.BaseRTMPClientHandler$CreateStreamCallBack.resultReceived(BaseRTMPClientHandler.java:1038)
at org.red5.server.net.rtmp.BaseRTMPHandler.handlePendingCallResult(BaseRTMPHandler.java:251)
at org.red5.client.net.rtmp.BaseRTMPClientHandler.onCommand(BaseRTMPClientHandler.java:780)
at org.apache.openmeetings.screenshare.RTMPScreenShare.onCommand(RTMPScreenShare.java:57)
at org.red5.server.net.rtmp.BaseRTMPHandler.messageReceived(BaseRTMPHandler.java:116)
at org.red5.server.net.rtmp.ReceivedMessageTask.call(ReceivedMessageTask.java:72)
at org.red5.server.net.rtmp.ReceivedMessageTask.call(ReceivedMessageTask.java:38)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Also the first recording is not playing.