Unknown Jenkins Exception Popping up at irregular intervals

Hi,

I’m getting this exception sometimes when I try to give a build. It doesn’t occur every time, only occurs once in a while. Can anyone know why this exception occurs and how to resolve this?

an exception which occurred:
	in field com.cloudbees.groovy.cps.impl.BlockScopeEnv.locals
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@7b8a2e4
	in field com.cloudbees.groovy.cps.impl.CallEnv.caller
	in object com.cloudbees.groovy.cps.impl.FunctionCallEnv@65bb8aa2
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@6f8c131a
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.LoopBlockScopeEnv@55232ec6
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@2fe02a9f
	in field com.cloudbees.groovy.cps.impl.CallEnv.caller
	in object com.cloudbees.groovy.cps.impl.ClosureCallEnv@2c531eb7
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@60cbc09a
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@3730c7ff
	in field com.cloudbees.groovy.cps.impl.CallEnv.caller
	in object com.cloudbees.groovy.cps.impl.FunctionCallEnv@406186a2
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@7dc54d3e
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.LoopBlockScopeEnv@6fb7f598
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@5ccf7e45
	in field com.cloudbees.groovy.cps.impl.CallEnv.caller
	in object com.cloudbees.groovy.cps.impl.ClosureCallEnv@13a0248
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@7e84cc59
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@331987af
	in field com.cloudbees.groovy.cps.impl.CallEnv.caller
	in object com.cloudbees.groovy.cps.impl.FunctionCallEnv@2fbc5d88
	in field com.cloudbees.groovy.cps.impl.ProxyEnv.parent
	in object com.cloudbees.groovy.cps.impl.BlockScopeEnv@43959fb0
	in field com.cloudbees.groovy.cps.impl.CallEnv.caller
	in object com.cloudbees.groovy.cps.impl.FunctionCallEnv@117fb755
	in field com.cloudbees.groovy.cps.Continuable.e
	in object org.jenkinsci.plugins.workflow.cps.SandboxContinuable@5eab05f4
	in field org.jenkinsci.plugins.workflow.cps.CpsThread.program
	in object org.jenkinsci.plugins.workflow.cps.CpsThread@2d1caad9
	in field org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.threads
	in object org.jenkinsci.plugins.workflow.cps.CpsThreadGroup@6fa3e1e4
	in object org.jenkinsci.plugins.workflow.cps.CpsThreadGroup@6fa3e1e4
Caused: java.io.NotSerializableException: hudson.plugins.git.GitChangeSetList
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:926)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:568)
	at org.jboss.marshalling.river.BlockMarshaller.doWriteObject(BlockMarshaller.java:65)
	at org.jboss.marshalling.river.BlockMarshaller.writeObject(BlockMarshaller.java:56)
	at org.jboss.marshalling.MarshallerObjectOutputStream.writeObjectOverride(MarshallerObjectOutputStream.java:50)
	at org.jboss.marshalling.river.RiverObjectOutputStream.writeObjectOverride(RiverObjectOutputStream.java:179)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:344)
	at java.util.HashMap.internalWriteEntries(HashMap.java:1793)
	at java.util.HashMap.writeObject(HashMap.java:1363)
	at sun.reflect.GeneratedMethodAccessor362.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.jboss.marshalling.reflect.JDKSpecific$SerMethods.callWriteObject(JDKSpecific.java:156)
	at org.jboss.marshalling.reflect.SerializableClass.callWriteObject(SerializableClass.java:191)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1028)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.BlockMarshaller.doWriteObject(BlockMarshaller.java:65)
	at org.jboss.marshalling.river.BlockMarshaller.writeObject(BlockMarshaller.java:56)
	at org.jboss.marshalling.MarshallerObjectOutputStream.writeObjectOverride(MarshallerObjectOutputStream.java:50)
	at org.jboss.marshalling.river.RiverObjectOutputStream.writeObjectOverride(RiverObjectOutputStream.java:179)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:344)
	at java.util.concurrent.ConcurrentSkipListMap.writeObject(ConcurrentSkipListMap.java:1437)
	at sun.reflect.GeneratedMethodAccessor380.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.jboss.marshalling.reflect.JDKSpecific$SerMethods.callWriteObject(JDKSpecific.java:156)
	at org.jboss.marshalling.reflect.SerializableClass.callWriteObject(SerializableClass.java:191)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1028)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1082)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1040)
	at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:920)
	at org.jboss.marshalling.AbstractObjectOutput.writeObject(AbstractObjectOutput.java:58)
	at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:111)
	at org.jenkinsci.plugins.workflow.support.pickles.serialization.RiverWriter.lambda$writeObject$0(RiverWriter.java:144)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:237)
	at org.jenkinsci.plugins.workflow.support.pickles.serialization.RiverWriter.writeObject(RiverWriter.java:143)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgram(CpsThreadGroup.java:559)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgram(CpsThreadGroup.java:536)
	at org.jenkinsci.plugins.workflow.cps.CpsStepContext$3.onSuccess(CpsStepContext.java:562)
	at org.jenkinsci.plugins.workflow.cps.CpsStepContext$3.onSuccess(CpsStepContext.java:556)
	at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution$4$1.run(CpsFlowExecution.java:917)
	at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$1.run(CpsVmExecutorService.java:38)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
	at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
	at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)