NullPointerException while executed javascript returns null to js-client

17:25:26,127 ERROR [org.infinispan.server.hotrod.HotRodEncoder] (HotRodServerWorker-7-119) ISPN005022: Exception writing response with messageId=188: java.lang.NullPointerException
	at org.infinispan.server.core.transport.ExtendedByteBuf$.writeRangedBytes(ExtendedByteBuf.scala:65)
	at org.infinispan.server.hotrod.Encoder2x$.writeResponse(Encoder2x.scala:340)
	at org.infinispan.server.hotrod.HotRodEncoder.encode(HotRodEncoder.scala:45)
	at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:107)
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:633)
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:691)
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:681)
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:716)
	at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:954)
	at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:243)
	at org.infinispan.server.hotrod.HotRodDecoder.writeResponse(HotRodDecoder.scala:250)
	at org.infinispan.server.hotrod.HotRodDecoder.customDecodeHeader(HotRodDecoder.scala:209)
	at org.infinispan.server.hotrod.HotRodDecoder.org$infinispan$server$hotrod$HotRodDecoder$$decodeHeader(HotRodDecoder.scala:97)
	at org.infinispan.server.hotrod.HotRodDecoder$$anonfun$decode$1.apply$mcV$sp(HotRodDecoder.scala:52)
	at org.infinispan.server.hotrod.HotRodDecoder.wrapSecurity(HotRodDecoder.scala:224)
	at org.infinispan.server.hotrod.HotRodDecoder.decode(HotRodDecoder.scala:50)
	at io.netty.handler.codec.ReplayingDecoder.callDecode(ReplayingDecoder.java:370)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:168)
	at org.infinispan.server.hotrod.HotRodDecoder.org$infinispan$server$core$transport$StatsChannelHandler$$super$channelRead(HotRodDecoder.scala:32)
	at org.infinispan.server.core.transport.StatsChannelHandler$class.channelRead(StatsChannelHandler.scala:32)
	at org.infinispan.server.hotrod.HotRodDecoder.channelRead(HotRodDecoder.scala:32)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:308)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:294)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:846)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:130)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
	at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
	at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137)
	at java.lang.Thread.run(Thread.java:745)

//Executable javascript: 

// mode=local,language=javascript,datatype='text/plain; charset=utf-8'
cacheManager.getAddress()


And the Test: 

it('can execute a script remotely to get node address from cacheManager', function(done) {
    Promise.all([client, readFile('spec/utils/test-cacheManager.js')])
        .then(function(vals) {
          var c = vals[0];
          return c.addScript('test-cacheManager.js', vals[1].toString())
              .then(function() { return c; } );
        })
        .then(t.assert(t.exec('test-cacheManager.js'),
                       t.toBeUndefined))
        .catch(failed(done)).finally(done);
  });

Message:
     java.lang.NullPointerException
   Stacktrace:
     undefined