title: The group member's supported protocols are incompatible with those of existing members
body: <p>I'm facing an issue related to Kafka.</p>
  
  <p>I'm having my current service (<code>Producer</code>) that sends the message to a Kafka topic (<code>events</code>). The service is using <code>kafka_2.12 v1.0.0</code>, written in Java.</p>
  
  <p>I'm trying to integrate it with the sample project of <code>spark-streaming</code> as a <code>Consumer</code> service (<a href="https://github.com/jjmeyer0/spark-streaming-example" rel="noreferrer">here</a> using kafka_2.11 v0.10.0, written in Scala)</p>
  
  <p>The message is sent successfully from <code>Producer</code> to the Kafka topic. However, I always receive the error stack below:</p>
  
  <pre><code>Exception in thread "main" org.apache.kafka.common.errors.InconsistentGroupProtocolException: The group member's supported protocols are incompatible with those of existing members.
      at ... run in separate thread using org.apache.spark.util.ThreadUtils ... ()
      at org.apache.spark.streaming.StreamingContext.liftedTree1$1(StreamingContext.scala:577)
      at org.apache.spark.streaming.StreamingContext.start(StreamingContext.scala:571)    at com.jj.streaming.ItemApp$.delayedEndpoint$com$jj$streaming$ItemApp$1(ItemApp.scala:72)
      at com.jj.streaming.ItemApp$delayedInit$body.apply(ItemApp.scala:12)
      at scala.Function0$class.apply$mcV$sp(Function0.scala:34)
      at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)     at scala.App$$anonfun$main$1.apply(App.scala:76)
      at scala.App$$anonfun$main$1.apply(App.scala:76)
      at scala.collection.immutable.List.foreach(List.scala:381)
      at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35)   at scala.App$class.main(App.scala:76)
      at com.jj.streaming.ItemApp$.main(ItemApp.scala:12)
      at com.jj.streaming.ItemApp.main(ItemApp.scala)
  </code></pre>
  
  <p>I don't know the root cause. How can I fix this?</p>