Trying to check a header response value but getting NPE

.check(header(“blahblah”).is(“00”))

works fine, as its always 00.

However I also want to check this when we get a 500 code, so I do

.check(status.in(200 to 500))

before it

But then I get an NPE

[ERROR] [08/18/2013 15:32:04.542] [GatlingSystem-akka.actor.default-dispatcher-21] [akka://GatlingSystem/user/$g] null
java.lang.NullPointerException
at scala.collection.convert.Wrappers$JListWrapper.length(Wrappers.scala:85)
at scala.collection.GenSeqLike$class.isDefinedAt(GenSeqLike.scala:71)
at scala.collection.AbstractSeq.isDefinedAt(Seq.scala:40)
at scala.collection.mutable.AbstractBuffer.isDefinedAt(Buffer.scala:48)
at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:118)
at scala.collection.AbstractSeq.applyOrElse(Seq.scala:40)
at scala.PartialFunction$Lifted.apply(PartialFunction.scala:218)
at scala.PartialFunction$Lifted.apply(PartialFunction.scala:214)
at io.gatling.http.check.header.HttpHeaderExtractors$$anonfun$1$$anon$1.apply(HttpHeaderExtractors.scala:44)
at io.gatling.http.check.header.HttpHeaderExtractors$$anonfun$1$$anon$1.apply(HttpHeaderExtractors.scala:41)
at io.gatling.core.check.CheckBase$$anonfun$check$3$$anonfun$apply$4.apply(Check.scala:65)
at io.gatling.core.check.CheckBase$$anonfun$check$3$$anonfun$apply$4.apply(Check.scala:64)
at io.gatling.core.validation.Success.flatMap(Validation.scala:27)
at io.gatling.core.check.CheckBase$$anonfun$check$3.apply(Check.scala:64)
at io.gatling.core.check.CheckBase$$anonfun$check$3.apply(Check.scala:63)
at io.gatling.core.validation.Success.flatMap(Validation.scala:27)
at io.gatling.core.check.CheckBase.check(Check.scala:63)
at io.gatling.http.check.HttpCheck.check(HttpCheck.scala:30)
at io.gatling.http.check.HttpCheck.check(HttpCheck.scala:29)
at io.gatling.core.check.Checks$$anonfun$check$1$$anonfun$apply$1.apply(Check.scala:30)
at io.gatling.core.check.Checks$$anonfun$check$1$$anonfun$apply$1.apply(Check.scala:30)
at io.gatling.core.validation.Success.flatMap(Validation.scala:27)
at io.gatling.core.check.Checks$$anonfun$check$1.apply(Check.scala:30)
at io.gatling.core.check.Checks$$anonfun$check$1.apply(Check.scala:29)
at scala.collection.LinearSeqOptimized$class.foldLeft(LinearSeqOptimized.scala:111)
at scala.collection.immutable.List.foldLeft(List.scala:84)
at io.gatling.core.check.Checks$.check(Check.scala:29)
at io.gatling.http.ahc.AsyncHandlerActor.checkAndProceed$1(AsyncHandlerActor.scala:163)
at io.gatling.http.ahc.AsyncHandlerActor.io$gatling$http$ahc$AsyncHandlerActor$$processResponse(AsyncHandlerActor.scala:176)
at io.gatling.http.ahc.AsyncHandlerActor$$anonfun$receive$1.applyOrElse(AsyncHandlerActor.scala:55)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:425)
at akka.actor.ActorCell.invoke(ActorCell.scala:386)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:230)
at akka.dispatch.Mailbox.run(Mailbox.scala:212)
at akka.dispatch.ForkJoinExecutorConfigurator$MailboxExecutionTask.exec(AbstractDispatcher.scala:506)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

What am I doing wrong?

Thanks.

Dino.

Could you upgrade to M3a, please?