Failed to load plugin and start after update to 2.524

Hello everyone!

Yesterday, after years and years of successful updates from the debian APT repo, Jenkins failed to start after the update to 2.524.

From what i can see, the main problem is this: java.io.IOException: Failed to load: Matrix Authorization Strategy Plugin (matrix-auth 3.2.8) - I use this plugin. After that, there is java.io.IOException: Unable to read /var/lib/jenkins/config.xml, which i guess is caused by the inability of Jenkins to parse the config.xml file (the parts where matrix auth is configured), since permissions are ok, and I am able to read the file using the Jenkins user. I’ve tried downgrading to 2.251, 2.252, 2.253 without success.

Anyway, that’s my “analysis”, full error log below.

The system is Ubuntu 22.04 LTS and Jenkins is 2.524, installed from the Debian APT repo. I will provide more information if needed.

Here’s the error log:

Aug 21 17:51:56 ci jenkins[3885455]: Running from: /usr/share/java/jenkins.war
Aug 21 17:51:56 ci jenkins[3885455]: 2025-08-21 14:51:56.544+0000 [id=1]        INFO        winstone.Logger#logInternal: Beginning extraction from war file
Aug 21 17:51:56 ci jenkins[3885455]: 2025-08-21 14:51:56.584+0000 [id=1]        WARNING        o.e.j.ee9.nested.ContextHandler#setContextPath: Empty contextPath
Aug 21 17:51:56 ci jenkins[3885455]: 2025-08-21 14:51:56.618+0000 [id=1]        INFO        org.eclipse.jetty.server.Server#doStart: jetty-12.0.25; built: 2025-08-11T23:52:37.219Z; git: a862b76d8372e24205765182d9ae1d1d333ce2ea; jvm 17.0.16+8-Ubuntu-0ubuntu122.>
Aug 21 17:51:56 ci jenkins[3885455]: 2025-08-21 14:51:56.852+0000 [id=1]        INFO        o.e.j.e.w.StandardDescriptorProcessor#visitServlet: NO JSP Support for /, did not find org.eclipse.jetty.ee9.jsp.JettyJspServlet
Aug 21 17:51:56 ci jenkins[3885455]: 2025-08-21 14:51:56.885+0000 [id=1]        INFO        o.e.j.s.DefaultSessionIdManager#doStart: Session workerName=node0
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.079+0000 [id=1]        INFO        hudson.WebAppMain#contextInitialized: Jenkins home directory: /var/lib/jenkins found at: EnvVars.masterEnvVars.get("JENKINS_HOME")
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.124+0000 [id=1]        INFO        o.e.j.s.handler.ContextHandler#doStart: Started oeje9n.ContextHandler$CoreContextHandler@41beb473{Jenkins v2.524,/,b=file:///var/cache/jenkins/war/,a=AVAILABLE,h=oeje9n>
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.130+0000 [id=1]        INFO        o.e.j.server.AbstractConnector#doStart: Started ServerConnector@13579834{HTTP/1.1, (http/1.1)}{0.0.0.0:8090}
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.134+0000 [id=1]        INFO        org.eclipse.jetty.server.Server#doStart: Started oejs.Server@d706f19{STARTING}[12.0.25,sto=0] @885ms
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.134+0000 [id=35]        INFO        winstone.Logger#logInternal: Winstone Servlet Engine running: controlPort=disabled
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.207+0000 [id=33]        INFO        jenkins.model.Jenkins#<init>: Starting version 2.524
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.251+0000 [id=40]        INFO        hudson.PluginManager#loadDetachedPlugins: Upgrading Jenkins. The last running version was 2.521. This Jenkins is version 2.524.
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.267+0000 [id=40]        INFO        hudson.PluginManager#loadDetachedPlugins: Upgraded Jenkins from version 2.521 to version 2.524. Loaded detached plugins (and dependencies): []
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.283+0000 [id=41]        INFO        jenkins.InitReactorRunner$1#onAttained: Started initialization
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.331+0000 [id=70]        INFO        jenkins.InitReactorRunner$1#onAttained: Listed all plugins
Aug 21 17:51:57 ci jenkins[3885455]: 2025-08-21 14:51:57.565+0000 [id=64]        SEVERE        jenkins.InitReactorRunner$1#onTaskFailed: Failed Loading plugin Matrix Authorization Strategy Plugin v3.2.8 (matrix-auth)
Aug 21 17:51:57 ci jenkins[3885455]: java.io.IOException: Failed to load: Matrix Authorization Strategy Plugin (matrix-auth 3.2.8)
Aug 21 17:51:57 ci jenkins[3885455]:  - Update required: Folders Plugin (cloudbees-folder 6.1012.v79a_86a_1ea_c1f) to be updated to 6.1026.ve06dfa_cf31c3 or higher
Aug 21 17:51:57 ci jenkins[3885455]:         at hudson.PluginWrapper.resolvePluginDependencies(PluginWrapper.java:1020)
Aug 21 17:51:57 ci jenkins[3885455]:         at hudson.PluginManager$2$1$1.run(PluginManager.java:592)
Aug 21 17:51:57 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:175)
Aug 21 17:51:57 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:304)
Aug 21 17:51:57 ci jenkins[3885455]:         at jenkins.model.Jenkins$5.runTask(Jenkins.java:1151)
Aug 21 17:51:57 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:221)
Aug 21 17:51:57 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:120)
Aug 21 17:51:57 ci jenkins[3885455]:         at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
Aug 21 17:51:57 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
Aug 21 17:51:57 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
Aug 21 17:51:57 ci jenkins[3885455]:         at java.base/java.lang.Thread.run(Thread.java:840)
Aug 21 17:51:58 ci jenkins[3885455]: 2025-08-21 14:51:58.810+0000 [id=65]        INFO        jenkins.InitReactorRunner$1#onAttained: Prepared all plugins
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.223+0000 [id=64]        INFO        jenkins.InitReactorRunner$1#onAttained: Started all plugins
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.224+0000 [id=64]        INFO        jenkins.InitReactorRunner$1#onAttained: Augmented all extensions
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.229+0000 [id=62]        SEVERE        jenkins.InitReactorRunner$1#onTaskFailed: Failed Loading global config
Aug 21 17:51:59 ci jenkins[3885455]: com.thoughtworks.xstream.mapper.CannotResolveClassException: hudson.security.GlobalMatrixAuthorizationStrategy
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:81)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.XStream2$CompatibilityMapper.realClass(XStream2.java:452)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.xstream.MapperDelegate.realClass(MapperDelegate.java:46)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:47)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.determineType(RobustReflectionConverter.java:551)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:349)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: jenkins.util.xstream.CriticalXStreamException:
Aug 21 17:51:59 ci jenkins[3885455]: ---- Debugging information ----
Aug 21 17:51:59 ci jenkins[3885455]: cause-exception     : com.thoughtworks.xstream.mapper.CannotResolveClassException
Aug 21 17:51:59 ci jenkins[3885455]: cause-message       : hudson.security.GlobalMatrixAuthorizationStrategy
Aug 21 17:51:59 ci jenkins[3885455]: class               : hudson.model.Hudson
Aug 21 17:51:59 ci jenkins[3885455]: required-type       : hudson.model.Hudson
Aug 21 17:51:59 ci jenkins[3885455]: converter-type      : hudson.util.RobustReflectionConverter
Aug 21 17:51:59 ci jenkins[3885455]: path                : /hudson/authorizationStrategy
Aug 21 17:51:59 ci jenkins[3885455]: line number         : 16
Aug 21 17:51:59 ci jenkins[3885455]: version             : 2.524
Aug 21 17:51:59 ci jenkins[3885455]: -------------------------------
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:384)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:291)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:52)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:136)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1468)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.XStream2.unmarshal(XStream2.java:230)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.XStream2.unmarshal(XStream2.java:201)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1445)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.unmarshal(XmlFile.java:196)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: java.io.IOException: Unable to read /var/lib/jenkins/config.xml
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.unmarshal(XmlFile.java:199)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.unmarshal(XmlFile.java:179)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins.load(Jenkins.java:3367)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins$13.run(Jenkins.java:3486)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:175)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:304)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins$5.runTask(Jenkins.java:1151)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:221)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:120)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.lang.Thread.run(Thread.java:840)
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.232+0000 [id=33]        SEVERE        hudson.util.BootFailure#publish: Failed to initialize Jenkins
Aug 21 17:51:59 ci jenkins[3885455]: com.thoughtworks.xstream.mapper.CannotResolveClassException: hudson.security.GlobalMatrixAuthorizationStrategy
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:81)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.XStream2$CompatibilityMapper.realClass(XStream2.java:452)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.xstream.MapperDelegate.realClass(MapperDelegate.java:46)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:125)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:47)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.determineType(RobustReflectionConverter.java:551)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:349)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: jenkins.util.xstream.CriticalXStreamException:
Aug 21 17:51:59 ci jenkins[3885455]: ---- Debugging information ----
Aug 21 17:51:59 ci jenkins[3885455]: cause-exception     : com.thoughtworks.xstream.mapper.CannotResolveClassException
Aug 21 17:51:59 ci jenkins[3885455]: cause-message       : hudson.security.GlobalMatrixAuthorizationStrategy
Aug 21 17:51:59 ci jenkins[3885455]: class               : hudson.model.Hudson
Aug 21 17:51:59 ci jenkins[3885455]: required-type       : hudson.model.Hudson
Aug 21 17:51:59 ci jenkins[3885455]: converter-type      : hudson.util.RobustReflectionConverter
Aug 21 17:51:59 ci jenkins[3885455]: path                : /hudson/authorizationStrategy
Aug 21 17:51:59 ci jenkins[3885455]: line number         : 16
Aug 21 17:51:59 ci jenkins[3885455]: version             : 2.524
Aug 21 17:51:59 ci jenkins[3885455]: -------------------------------
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:384)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:291)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:52)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:136)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1468)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.XStream2.unmarshal(XStream2.java:230)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.XStream2.unmarshal(XStream2.java:201)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1445)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.unmarshal(XmlFile.java:196)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: java.io.IOException: Unable to read /var/lib/jenkins/config.xml
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.unmarshal(XmlFile.java:199)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.unmarshal(XmlFile.java:179)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins.load(Jenkins.java:3367)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins$13.run(Jenkins.java:3486)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:175)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:304)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins$5.runTask(Jenkins.java:1151)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:221)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:120)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.lang.Thread.run(Thread.java:840)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: org.jvnet.hudson.reactor.ReactorException
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:290)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.InitReactorRunner.run(InitReactorRunner.java:49)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins.executeReactor(Jenkins.java:1186)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins.<init>(Jenkins.java:985)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.model.Hudson.<init>(Hudson.java:100)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.model.Hudson.<init>(Hudson.java:85)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.WebAppMain$3.run(WebAppMain.java:249)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: hudson.util.HudsonFailedToLoad
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.WebAppMain$3.run(WebAppMain.java:277)
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.236+0000 [id=44]        WARNING        hudson.model.UpdateCenter#save: Failed to save /var/lib/jenkins/hudson.model.UpdateCenter.xml
Aug 21 17:51:59 ci jenkins[3885455]: java.nio.channels.ClosedChannelException
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/sun.nio.ch.FileChannelImpl.ensureOpen(FileChannelImpl.java:159)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/sun.nio.ch.FileChannelImpl.write(FileChannelImpl.java:274)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.FileChannelWriter.write(FileChannelWriter.java:73)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.AtomicFileWriter.write(AtomicFileWriter.java:185)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.util.QuickWriter.flush(QuickWriter.java:73)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: com.thoughtworks.xstream.io.StreamException:
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.core.util.QuickWriter.flush(QuickWriter.java:77)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.PrettyPrintWriter.flush(PrettyPrintWriter.java:322)
Aug 21 17:51:59 ci jenkins[3885455]:         at com.thoughtworks.xstream.XStream.toXML(XStream.java:1271)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.write(XmlFile.java:216)
Aug 21 17:51:59 ci jenkins[3885455]: Caused: java.io.IOException
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.XmlFile.write(XmlFile.java:223)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.model.UpdateCenter.save(UpdateCenter.java:1017)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.PersistedList.onModified(PersistedList.java:190)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.util.PersistedList.replaceBy(PersistedList.java:96)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.model.UpdateCenter.load(UpdateCenter.java:1032)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.model.UpdateCenter.init(UpdateCenter.java:2880)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.lang.reflect.Method.invoke(Method.java:569)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.init.TaskMethodFinder.invoke(TaskMethodFinder.java:109)
Aug 21 17:51:59 ci jenkins[3885455]:         at hudson.init.TaskMethodFinder$TaskImpl.run(TaskMethodFinder.java:185)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:304)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.model.Jenkins$5.runTask(Jenkins.java:1151)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:221)
Aug 21 17:51:59 ci jenkins[3885455]:         at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:120)
Aug 21 17:51:59 ci jenkins[3885455]:         at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
Aug 21 17:51:59 ci jenkins[3885455]:         at java.base/java.lang.Thread.run(Thread.java:840)
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.242+0000 [id=33]        INFO        hudson.lifecycle.Lifecycle#onStatusUpdate: Stopping Jenkins
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.250+0000 [id=33]        INFO        jenkins.model.Jenkins$17#onAttained: Started termination
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.258+0000 [id=33]        INFO        jenkins.model.Jenkins$17#onAttained: Completed termination
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.258+0000 [id=33]        INFO        jenkins.model.Jenkins#_cleanUpDisconnectComputers: Starting node disconnection
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.259+0000 [id=33]        INFO        jenkins.model.Jenkins#_cleanUpShutdownPluginManager: Stopping plugin manager
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.261+0000 [id=33]        INFO        jenkins.model.Jenkins#_cleanUpPersistQueue: Persisting build queue
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.268+0000 [id=33]        INFO        hudson.lifecycle.Lifecycle#onStatusUpdate: Jenkins stopped
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.268+0000 [id=36]        INFO        winstone.Logger#logInternal: JVM is terminating. Shutting down Jetty
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.269+0000 [id=36]        INFO        org.eclipse.jetty.server.Server#doStop: Stopped oejs.Server@d706f19{STOPPING}[12.0.25,sto=0]
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.270+0000 [id=36]        INFO        o.e.j.server.AbstractConnector#doStop: Stopped ServerConnector@13579834{HTTP/1.1, (http/1.1)}{0.0.0.0:8090}
Aug 21 17:51:59 ci jenkins[3885455]: 2025-08-21 14:51:59.273+0000 [id=36]        INFO        hudson.WebAppMain#contextDestroyed: Shutting down a Jenkins instance that was still starting up
...

The problem is that matrix-auth needs a newer version of the folders plugin as stated in the logs. As a result it can’t be loaded. The config.xml now can’t be read as it contains the configuration for matrix-auth
You should downloaded the latest version of the folders plugin (https://updates.jenkins.io/download/plugins/cloudbees-folder/6.1037.v4cb_8573b_72a_a_/cloudbees-folder.hpi) and put that file in the plugins folder of your Jenkins instance (rename the old cloudbees-folder.jpi first to .bak and then rename to .jpi)

Thank you, that solved the problem!