Considering this fixed given it didn't resurface since early December 2018.

Hello Folks,

the Bug is not fixed.

With jenkins-Installation 2.268 occurs the same error. Jenkins run under Java 11

openjdk version "11.0.9.1" 2020-11-04
OpenJDK Runtime Environment (build 11.0.9.1+1-Ubuntu-0ubuntu1.20.04)
OpenJDK 64-Bit Server VM (build 11.0.9.1+1-Ubuntu-0ubuntu1.20.04, mixed mode, sharing)

Output from Jenkins Job console.
Started by user
Sascha Jostock
> /opt/gitlab/embedded/bin/git rev-parse --is-inside-work-tree # timeout=10
Setting origin to git@saturn.sajoconsulting.local:sajo-consulting/produkte/workfluency.git
> /opt/gitlab/embedded/bin/git config remote.origin.url git@saturn.sajoconsulting.local:sajo-consulting/produkte/workfluency.git # timeout=10
Fetching origin...
Fetching upstream changes from origin
> /opt/gitlab/embedded/bin/git --version # timeout=10
> git --version # 'git version 2.28.0'
> /opt/gitlab/embedded/bin/git config --get remote.origin.url # timeout=10
> /opt/gitlab/embedded/bin/git fetch --tags --force --progress – origin +refs/heads/:refs/remotes/origin/ # timeout=10
Seen branch in repository master/development
Seen branch in repository master/feature/mahah001/WOR-11-einrichten-eines-jenkins-job-fuer-workfluency-den-master-und-dev-bauen
Seen branch in repository master/feature/mahah001/WOR-7-sonderzeichen-in-kommentaren-entfernen
Seen branch in repository master/master
Seen branch in repository origin/development
Seen branch in repository origin/feature/mahah001/WOR-21-deploy-in-wildfly-ueber-maven-plugin
Seen branch in repository origin/master
Seen 7 remote branches
Obtained Jenkinsfile from bc394c2348e2775ebb840d73e8a27e396427edb2
Running in Durability level: MAX_SURVIVABILITY[Pipeline] Start of Pipeline[Pipeline] node[Pipeline] End of PipelineRunning on Jenkins in /var/lib/jenkins/workspace/kfluency_Multibranch_development@3java.lang.NoClassDefFoundError: Could not initialize class org.jboss.marshalling.river.RiverMarshaller
at org.jboss.marshalling.river.RiverMarshallerFactory.createMarshaller(RiverMarshallerFactory.java:54)
at org.jenkinsci.plugins.workflow.support.pickles.serialization.RiverWriter.<init>(RiverWriter.java:136)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgram(CpsThreadGroup.java:556)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgram(CpsThreadGroup.java:534)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.saveProgramIfPossible(CpsThreadGroup.java:517)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:441)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)
at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
Finished: FAILURE

Currently not working

Please create a new issue. It is likely a regression after a library update. We will also need plugin versions

I created JENKINS-67848 as I just saw it a few moments ago.