Coap create request without requestIdentifier, no response back

Coap create request without requestIdentifier, no response back. Iotdm logs the error below:
java.lang.NullPointerException
at org.eclipse.californium.core.coap.Option.setStringValue(Option.java:212)
at org.eclipse.californium.core.coap.Option.<init>(Option.java:83)
at org.opendaylight.iotdm.onem2m.protocols.coap.Onem2mCoapProvider$RootResource.sendCoapResponseFromOnem2mResponse(Onem2mCoapProvider.java:174)
at org.opendaylight.iotdm.onem2m.protocols.coap.Onem2mCoapProvider$RootResource.handleRequest(Onem2mCoapProvider.java:161)
at org.eclipse.californium.core.server.ServerMessageDeliverer.deliverRequest(ServerMessageDeliverer.java:79)
at org.eclipse.californium.core.network.stack.CoapStack$StackTopAdapter.receiveRequest(CoapStack.java:179)
at org.eclipse.californium.core.network.stack.AbstractLayer.receiveRequest(AbstractLayer.java:88)
at org.eclipse.californium.core.network.stack.AbstractLayer.receiveRequest(AbstractLayer.java:88)
at org.eclipse.californium.core.network.stack.BlockwiseLayer.receiveRequest(BlockwiseLayer.java:238)
at org.eclipse.californium.core.network.stack.AbstractLayer.receiveRequest(AbstractLayer.java:88)
at org.eclipse.californium.core.network.stack.TokenLayer.receiveRequest(TokenLayer.java:75)
at org.eclipse.californium.core.network.stack.AbstractLayer.receiveRequest(AbstractLayer.java:88)
at org.eclipse.californium.core.network.stack.ReliabilityLayer.receiveRequest(ReliabilityLayer.java:198)
at org.eclipse.californium.core.network.stack.AbstractLayer.receiveRequest(AbstractLayer.java:88)
at org.eclipse.californium.core.network.stack.CoapStack.receiveRequest(CoapStack.java:132)
at org.eclipse.californium.core.network.CoAPEndpoint$InboxImpl.receiveMessage(CoAPEndpoint.java:569)
at org.eclipse.californium.core.network.CoAPEndpoint$InboxImpl.access$700(CoAPEndpoint.java:505)
at org.eclipse.californium.core.network.CoAPEndpoint$InboxImpl$1.run(CoAPEndpoint.java:517)
at org.eclipse.californium.core.network.CoAPEndpoint$4.run(CoAPEndpoint.java:649)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)