ClosureCleaner console stdout/stderr, scala 2.11.11

ClosureCleaner.console

Cleaning native Java map
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Cleaning map converted by JavaConverters
Exception in thread "main" org.apache.flink.api.common.InvalidProgramException: {key1=value1} is not serializable. The object probably contains or references non serializable fields.
	at org.apache.flink.api.java.ClosureCleaner.clean(ClosureCleaner.java:100)
	at MWE$.delayedEndpoint$MWE$1(MWE.scala:17)
	at MWE$delayedInit$body.apply(MWE.scala:5)
	at scala.Function0$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$1.apply(App.scala:76)
	at scala.collection.immutable.List.foreach(List.scala:392)
	at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35)
	at scala.App$class.main(App.scala:76)
	at MWE$.main(MWE.scala:5)
	at MWE.main(MWE.scala)
Caused by: java.io.NotSerializableException: scala.collection.convert.Wrappers$MapWrapper
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
	at org.apache.flink.util.InstantiationUtil.serializeObject(InstantiationUtil.java:315)
	at org.apache.flink.api.java.ClosureCleaner.clean(ClosureCleaner.java:81)
	... 11 more

Process finished with exit code 1