```
udson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException: java.lang.ClassCastException: org.jenkinsci.plugins.conditionalbuildstep.singlestep.SingleConditionalBuilder cannot be cast to hudson.tasks.Publisher
at hudson.WebAppMain$3.run(WebAppMain.java:237)
Caused by: org.jvnet.hudson.reactor.ReactorException: java.lang.ClassCastException: org.jenkinsci.plugins.conditionalbuildstep.singlestep.SingleConditionalBuilder cannot be cast to hudson.tasks.Publisher
at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269)
at jenkins.InitReactorRunner.run(InitReactorRunner.java:44)
at jenkins.model.Jenkins.executeReactor(Jenkins.java:935)
at jenkins.model.Jenkins.<init>(Jenkins.java:816)
at hudson.model.Hudson.<init>(Hudson.java:83)
at hudson.model.Hudson.<init>(Hudson.java:79)
at hudson.WebAppMain$3.run(WebAppMain.java:225)
Caused by: java.lang.ClassCastException: org.jenkinsci.plugins.conditionalbuildstep.singlestep.SingleConditionalBuilder cannot be cast to hudson.tasks.Publisher
at hudson.maven.MavenModule.getDependencyRelevancy(MavenModule.java:675)
at hudson.maven.MavenModule.chooseMoreRelevantModule(MavenModule.java:632)
at hudson.maven.MavenModule.buildDependencyGraph(MavenModule.java:515)
at hudson.model.DependencyGraph.build(DependencyGraph.java:95)
at jenkins.model.Jenkins.rebuildDependencyGraph(Jenkins.java:3816)
at jenkins.model.Jenkins$20.run(Jenkins.java:2742)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
at jenkins.model.Jenkins$8.runTask(Jenkins.java:924)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:210)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
```