Pipeline plugin error on supereasy Jenkins pipeline - jenkins

Question

I'm running this simple pipeline:
node ('main') {
echo 'Hello World'
}
And I'm having the following error on job:
Started by user Paco
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[Pipeline] node
Running on Jenkins in /opt/bitnami/apps/jenkins/jenkins_home/workspace/tespipeline
[Pipeline] End of Pipeline
an exception which occurred:
in field java.util.HashMap.loadFactor
in object java.util.HashMap#660dfa72
in field org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.closures
in object org.jenkinsci.plugins.workflow.cps.CpsThreadGroup#5f085500
in object org.jenkinsci.plugins.workflow.cps.CpsThreadGroup#5f085500
Caused: java.lang.IllegalAccessException: Class org.jboss.marshalling.river.RiverMarshaller can not access a member of class java.util.HashMap with modifiers "final"
at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:102)
at java.lang.reflect.AccessibleObject.slowCheckMemberAccess(AccessibleObject.java:296)
at java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:288)
at java.lang.reflect.Field.getFloat(Field.java:645)
at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1028)
Caused: java.io.InvalidObjectException: Unexpected illegal access exception
at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1037)
at org.jboss.marshalling.river.RiverObjectOutputStream.defaultWriteObject(RiverObjectOutputStream.java:165)
at java.util.HashMap.writeObject(HashMap.java:1360)
at sun.reflect.GeneratedMethodAccessor55.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$SerMethods.callWriteObject(JDKSpecific.java:156)
at org.jboss.marshalling.reflect.SerializableClass.callWriteObject(SerializableClass.java:191)
at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:976)
at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:854)
at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1032)
at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:988)
at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:854)
at org.jboss.marshalling.AbstractObjectOutput.writeObject(AbstractObjectOutput.java:58)
at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:111)
at org.jenkinsci.plugins.workflow.support.pickles.serialization.RiverWriter.lambda$writeObject$0(RiverWriter.java:144)
at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:136)
at org.jenkinsci.plugins.workflow.support.pickles.serialization.RiverWriter.writeObject(RiverWriter.java:143)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgram(CpsThreadGroup.java:482)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgram(CpsThreadGroup.java:458)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgramIfPossible(CpsThreadGroup.java:445)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:372)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$200(CpsThreadGroup.java:83)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:244)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:232)
at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:64)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:131)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
at java.util.concurrent.Executors$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)
Finished: FAILURE
My actual Jenkins version is 2.164.1 (the newer one), the pipeline version that I have installed is 2.6, but I also tried a previous one.
I also tried with google without luck.
Any idea about the problem?

Answer 1

First, make sure you have declared a pipeline, then you can use stages, stage and steps, finally, run your pipeline.
I give you the following test code below.
pipeline {
agent any
stages {
stage('Build') {
steps {
echo 'Building..'
}
}
stage('Test') {
steps {
echo 'Testing..'
}
}
stage('Deploy') {
steps {
echo 'Deploying....'
}
}
}
}
If you need to use node, you can use the following examples
I hope it may help you!

Answer 2

Your script is not a valid scripted pipeline syntax. See documentation
A node should contain a stage, then the steps
node('main'){
stage('Print message'){
echo 'Hello world!'
}
}

Answer 3

I found the solution, it was a problem with user permission in SO level. I've created a new instance and added a backup to it without changing the permission of the jenkins executor user, and it is working like a charm.
Thank you all, for your responses!