Hi there.
I captured an issue according to JEP-200 using Multibranch Pipeline with Gerrit-Code-Review.
I can apply a workaround, but I would like it if the maintainer can resolve the issue for safety reasons.

Log:

17:04:02 Running on host01 in /home/jenkins/workspace/Playground_aaaa_81_82381_2@6
17:04:02 java.lang.UnsupportedOperationException: Refusing to marshal com.google.gerrit.extensions.common.ReviewerUpdateInfo for security reasons; see https://www.jenkins.io/redirect/class-filter/
17:04:02 at hudson.util.XStream2$BlacklistedTypesConverter.marshal(XStream2.java:581)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:44)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:87)
17:04:02 at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeBareItem(AbstractCollectionConverter.java:94)
17:04:02 at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeItem(AbstractCollectionConverter.java:66)
17:04:02 at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeCompleteItem(AbstractCollectionConverter.java:81)
17:04:02 at com.thoughtworks.xstream.converters.collections.CollectionConverter.marshal(CollectionConverter.java:75)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:83)
17:04:02 at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:283)
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:270)
17:04:02 Caused: java.lang.RuntimeException: Failed to serialize com.google.gerrit.extensions.common.ChangeInfo#reviewerUpdates for class com.google.gerrit.extensions.common.ChangeInfo
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:274)
17:04:02 at hudson.util.RobustReflectionConverter$2.visit(RobustReflectionConverter.java:241)
17:04:02 at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:174)
17:04:02 at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:226)
17:04:02 at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:163)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:83)
17:04:02 at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:283)
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:270)
17:04:02 Caused: java.lang.RuntimeException: Failed to serialize java.util.Optional#value for class java.util.Optional
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:274)
17:04:02 at hudson.util.RobustReflectionConverter$2.visit(RobustReflectionConverter.java:241)
17:04:02 at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:174)
17:04:02 at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:226)
17:04:02 at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:163)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:83)
17:04:02 at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:283)
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:270)
17:04:02 Caused: java.lang.RuntimeException: Failed to serialize jenkins.plugins.gerrit.GerritEnvironmentContributor$ChangeInfoInvisibleAction#maybeChangeInfo for class jenkins.plugins.gerrit.GerritEnvironmentContributor$ChangeInfoInvisibleAction
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:274)
17:04:02 at hudson.util.RobustReflectionConverter$2.visit(RobustReflectionConverter.java:241)
17:04:02 at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:174)
17:04:02 at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:226)
17:04:02 at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:163)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:44)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:87)
17:04:02 at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeBareItem(AbstractCollectionConverter.java:94)
17:04:02 at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeItem(AbstractCollectionConverter.java:66)
17:04:02 at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeCompleteItem(AbstractCollectionConverter.java:81)
17:04:02 at com.thoughtworks.xstream.converters.collections.CollectionConverter.marshal(CollectionConverter.java:75)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:83)
17:04:02 at hudson.util.RobustReflectionConverter.marshallField(RobustReflectionConverter.java:283)
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:270)
17:04:02 Caused: java.lang.RuntimeException: Failed to serialize hudson.model.Actionable#actions for class org.jenkinsci.plugins.workflow.job.WorkflowRun
17:04:02 at hudson.util.RobustReflectionConverter$2.writeField(RobustReflectionConverter.java:274)
17:04:02 at hudson.util.RobustReflectionConverter$2.visit(RobustReflectionConverter.java:241)
17:04:02 at com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider.visitSerializableFields(PureJavaReflectionProvider.java:174)
17:04:02 at hudson.util.RobustReflectionConverter.doMarshal(RobustReflectionConverter.java:226)
17:04:02 at hudson.util.RobustReflectionConverter.marshal(RobustReflectionConverter.java:163)
17:04:02 at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:68)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:59)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:44)
17:04:02 at com.thoughtworks.xstream.core.TreeMarshaller.start(TreeMarshaller.java:83)
17:04:02 at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.marshal(AbstractTreeMarshallingStrategy.java:37)
17:04:02 at com.thoughtworks.xstream.XStream.marshal(XStream.java:1266)
17:04:02 at com.thoughtworks.xstream.XStream.marshal(XStream.java:1255)
17:04:02 at com.thoughtworks.xstream.XStream.toXML(XStream.java:1228)
17:04:02 at hudson.util.XStream2.toXMLUTF8(XStream2.java:345)
17:04:02 at org.jenkinsci.plugins.workflow.support.PipelineIOUtils.writeByXStream(PipelineIOUtils.java:34)
17:04:02 at org.jenkinsci.plugins.workflow.job.WorkflowRun.save(WorkflowRun.java:1228)
17:04:02 at hudson.BulkChange.commit(BulkChange.java:98)
17:04:02 at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.notifyListeners(CpsFlowExecution.java:1472)
17:04:02 at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$3.run(CpsThreadGroup.java:509)
17:04:02 at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$1.run(CpsVmExecutorService.java:38)
17:04:02 at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
17:04:02 at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
17:04:02 at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
17:04:02 at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
17:04:02 at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
17:04:02 at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
17:04:02 at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
17:04:02 at java.base/java.lang.Thread.run(Thread.java:829)
17:04:02 Finished: FAILURE