I'm getting this error in v1.545 and v1.546.

java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchStandard(Launcher.java:329)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:239)
at org.jvnet.hudson.maven3.agent.Maven3Main.launch(Maven3Main.java:178)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at hudson.maven.Maven3Builder.call(Maven3Builder.java:134)
at hudson.maven.Maven3Builder.call(Maven3Builder.java:69)
at hudson.remoting.UserRequest.perform(UserRequest.java:118)
at hudson.remoting.UserRequest.perform(UserRequest.java:48)
at hudson.remoting.Request$2.run(Request.java:328)
at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.ExceptionInInitializerError
at edu.umd.cs.findbugs.DetectorFactoryCollection.getCoreResource(DetectorFactoryCollection.java:360)
at edu.umd.cs.findbugs.SystemProperties.loadPropertiesFromConfigFile(SystemProperties.java:72)
at edu.umd.cs.findbugs.SystemProperties.<clinit>(SystemProperties.java:55)
at edu.umd.cs.findbugs.SortedBugCollection.<clinit>(SortedBugCollection.java:189)
at hudson.plugins.findbugs.parser.FindBugsParser.readXml(FindBugsParser.java:282)
at hudson.plugins.findbugs.parser.FindBugsParser.parse(FindBugsParser.java:221)
at hudson.plugins.findbugs.parser.FindBugsParser.parse(FindBugsParser.java:159)
at hudson.plugins.findbugs.parser.FindBugsParser.parse(FindBugsParser.java:138)
at hudson.plugins.findbugs.parser.FindBugsParser.parse(FindBugsParser.java:105)
at hudson.plugins.analysis.core.FilesParser.parseFile(FilesParser.java:306)
at hudson.plugins.analysis.core.FilesParser.parseFiles(FilesParser.java:264)
at hudson.plugins.analysis.core.FilesParser.parserCollectionOfFiles(FilesParser.java:215)
at hudson.plugins.analysis.core.FilesParser.invoke(FilesParser.java:184)
at hudson.plugins.analysis.core.FilesParser.invoke(FilesParser.java:31)
at hudson.FilePath.act(FilePath.java:914)
at hudson.FilePath.act(FilePath.java:887)
at hudson.plugins.findbugs.FindBugsReporter.perform(FindBugsReporter.java:179)
at hudson.plugins.analysis.core.HealthAwareReporter.postExecute(HealthAwareReporter.java:315)
at hudson.maven.Maven3Builder$MavenExecutionListener.recordMojoEnded(Maven3Builder.java:628)
at hudson.maven.Maven3Builder$MavenExecutionListener.mojoSucceeded(Maven3Builder.java:610)
at org.apache.maven.lifecycle.internal.DefaultExecutionEventCatapult.fire(DefaultExecutionEventCatapult.java:87)
at org.apache.maven.lifecycle.internal.DefaultExecutionEventCatapult.fire(DefaultExecutionEventCatapult.java:42)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:228)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.jvnet.hudson.maven3.launcher.Maven3Launcher.main(Maven3Launcher.java:117)
... 22 more
Caused by: java.lang.IllegalStateException: Unable to load core plugin
at edu.umd.cs.findbugs.PluginLoader.loadCorePlugin(PluginLoader.java:1423)
at edu.umd.cs.findbugs.PluginLoader.loadInitialPlugins(PluginLoader.java:1373)
at edu.umd.cs.findbugs.PluginLoader.<clinit>(PluginLoader.java:156)
... 54 more
Caused by: edu.umd.cs.findbugs.PluginException: Couldn't parse "jar:file:/var/lib/jenkins/.jenkins/cache/jars/DB/BFFF630BEF40FBA05BFDA2CDC31BC1.jar!/findbugs.xml" using org.dom4j.io.SAXReader
at edu.umd.cs.findbugs.PluginLoader.getPluginDescriptor(PluginLoader.java:1122)
at edu.umd.cs.findbugs.PluginLoader.init(PluginLoader.java:611)
at edu.umd.cs.findbugs.PluginLoader.<init>(PluginLoader.java:357)
at edu.umd.cs.findbugs.PluginLoader.loadCorePlugin(PluginLoader.java:1419)
... 56 more
Caused by: org.dom4j.DocumentException: org.dom4j.DocumentFactory cannot be cast to org.dom4j.DocumentFactory Nested exception: org.dom4j.DocumentFactory cannot be cast to org.dom4j.DocumentFactory
at org.dom4j.io.SAXReader.read(SAXReader.java:484)
at org.dom4j.io.SAXReader.read(SAXReader.java:365)
at edu.umd.cs.findbugs.PluginLoader.getPluginDescriptor(PluginLoader.java:1120)
... 59 more
Caused by: java.lang.ClassCastException: org.dom4j.DocumentFactory cannot be cast to org.dom4j.DocumentFactory
at org.dom4j.DocumentFactory.getInstance(DocumentFactory.java:97)
at org.dom4j.io.SAXReader.getDocumentFactory(SAXReader.java:645)
at org.dom4j.io.SAXReader.createContentHandler(SAXReader.java:969)
at org.dom4j.io.SAXReader.read(SAXReader.java:449)
... 61 more