After update plugins, We cant init jenkins: 

The error is:

om.thoughtworks.xstream.mapper.CannotResolveClassException: hudson.security.LDAPSecurityRealm
at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:79)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at hudson.util.XStream2$CompatibilityMapper.realClass(XStream2.java:379)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at hudson.util.xstream.MapperDelegate.realClass(MapperDelegate.java:43)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:48)
at hudson.util.RobustReflectionConverter.determineType(RobustReflectionConverter.java:458)
at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:324)
Caused: jenkins.util.xstream.CriticalXStreamException: hudson.security.LDAPSecurityRealm : hudson.security.LDAPSecurityRealm
---- Debugging information ----
message : hudson.security.LDAPSecurityRealm
cause-exception : com.thoughtworks.xstream.mapper.CannotResolveClassException
cause-message : hudson.security.LDAPSecurityRealm
class : hudson.model.Hudson
required-type : hudson.model.Hudson
converter-type : hudson.util.RobustReflectionConverter
path : /hudson/securityRealm
line number : 17
version : not available
-------------------------------
at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:353)
at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:267)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1189)
at hudson.util.XStream2.unmarshal(XStream2.java:161)
at hudson.util.XStream2.unmarshal(XStream2.java:132)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1173)
at hudson.XmlFile.unmarshal(XmlFile.java:180)
Caused: java.io.IOException: Unable to read /var/jenkins_home/config.xml
at hudson.XmlFile.unmarshal(XmlFile.java:183)
at hudson.XmlFile.unmarshal(XmlFile.java:163)
at jenkins.model.Jenkins.loadConfig(Jenkins.java:3118)
at jenkins.model.Jenkins.access$1200(Jenkins.java:320)
at jenkins.model.Jenkins$13.run(Jenkins.java:3219)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:296)
at jenkins.model.Jenkins$5.runTask(Jenkins.java:1133)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:214)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused: org.jvnet.hudson.reactor.ReactorException
at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:282)
at jenkins.InitReactorRunner.run(InitReactorRunner.java:50)
at jenkins.model.Jenkins.executeReactor(Jenkins.java:1166)
at jenkins.model.Jenkins.<init>(Jenkins.java:966)
at hudson.model.Hudson.<init>(Hudson.java:85)
at hudson.model.Hudson.<init>(Hudson.java:81)
at hudson.WebAppMain$3.run(WebAppMain.java:233)
Caused: hudson.util.HudsonFailedToLoad
at hudson.WebAppMain$3.run(WebAppMain.java:250)

 

My config xml is

 

1. cat /var/jenkins_home/config.xml
   <?xml version='1.1' encoding='UTF-8'?>
   <hudson>
     <disabledAdministrativeMonitors/>
     <version>2.222.4</version>
     <installStateName>RUNNING</installStateName>
     <numExecutors>2</numExecutors>
     <mode>NORMAL</mode>
     <useSecurity>true</useSecurity>
     <authorizationStrategy class="hudson.security.ProjectMatrixAuthorizationStrategy">
       <permission>hudson.model.Hudson.Administer:jenkins-admin</permission>
       <permission>hudson.model.Hudson.Read:jenkins-user</permission>
       <permission>hudson.model.Item.Build:jenkins-user</permission>
       <permission>hudson.model.Item.Cancel:jenkins-user</permission>
       <permission>hudson.model.Item.Read:jenkins-user</permission>
     </authorizationStrategy>
     <securityRealm class="hudson.security.LDAPSecurityRealm" plugin="ldap@1.20">
       <disableMailAddressResolver>false</disableMailAddressResolver>
       <configurations>
         <jenkins.security.plugins.ldap.LDAPConfiguration>
           <server>xxx</server>
           <rootDN>dc=finametrix,dc=com</rootDN>
           <inhibitInferRootDN>false</inhibitInferRootDN>
           <userSearchBase>ou=users</userSearchBase>
           <userSearch>uid={0}</userSearch>
           <groupSearchBase>ou=groups</groupSearchBase>
           <groupMembershipStrategy class="jenkins.security.plugins.ldap.FromGroupSearchLDAPGroupMembershipStrategy">
             <filter>uniqueMember={0}</filter>
           </groupMembershipStrategy>
           <managerDN>cn=readonly,dc=finametrix,dc=com</managerDN>
           <managerPasswordSecret>{mysecret}</managerPasswordSecret>
           <displayNameAttributeName>displayname</displayNameAttributeName>
           <mailAddressAttributeName>mail</mailAddressAttributeName>
           <ignoreIfUnavailable>false</ignoreIfUnavailable>
         </jenkins.security.plugins.ldap.LDAPConfiguration>
       </configurations>
       <userIdStrategy class="jenkins.model.IdStrategy$CaseInsensitive"/>
       <groupIdStrategy class="jenkins.model.IdStrategy$CaseInsensitive"/>
       <disableRolePrefixing>true</disableRolePrefixing>
     </securityRealm>
     <disableRememberMe>false</disableRememberMe>
     <projectNamingStrategy class="jenkins.model.ProjectNamingStrategy$DefaultProjectNamingStrategy"/>
     <workspaceDir>${JENKINS_HOME}/workspace/${ITEM_FULL_NAME}</workspaceDir>
     <buildsDir>${ITEM_ROOTDIR}/builds</buildsDir>
     <markupFormatter class="hudson.markup.EscapedMarkupFormatter"/>
     <jdks/>
     <viewsTabBar class="hudson.views.DefaultViewsTabBar"/>
     <myViewsTabBar class="hudson.views.DefaultMyViewsTabBar"/>
     <clouds>
       <org.csanchez.jenkins.plugins.kubernetes.KubernetesCloud plugin="kubernetes@1.21.1">
         <name>kubernetes</name>
         <defaultsProviderTemplate>ubuntu</defaultsProviderTemplate>
         <templates>
           <org.csanchez.jenkins.plugins.kubernetes.PodTemplate>
             <inheritFrom></inheritFrom>
             <name>ubuntu</name>
             <namespace></namespace>
             <privileged>false</privileged>
             <capOnlyOnAlivePods>false</capOnlyOnAlivePods>
             <alwaysPullImage>false</alwaysPullImage>
             <instanceCap>2147483647</instanceCap>
             <slaveConnectTimeout>100</slaveConnectTimeout>
             <idleMinutes>0</idleMinutes>
             <activeDeadlineSeconds>600</activeDeadlineSeconds>
             <label></label>
             <nodeSelector></nodeSelector>
             <nodeUsageMode>EXCLUSIVE</nodeUsageMode>
             <hostNetwork>false</hostNetwork>
             <workspaceVolume class="org.csanchez.jenkins.plugins.kubernetes.volumes.workspace.EmptyDirWorkspaceVolume">
               <memory>false</memory>
             </workspaceVolume>
             <volumes/>
             <containers>
               <org.csanchez.jenkins.plugins.kubernetes.ContainerTemplate>
                 <name>ubuntu</name>
                 <image>docker.finametrix.com/ci/ubuntu:latest</image>
                 <privileged>false</privileged>
                 <alwaysPullImage>false</alwaysPullImage>
                 <workingDir>/home/jenkins/agent</workingDir>
                 <command>/bin/sh -c</command>
                 <args>cat</args>
                 <ttyEnabled>true</ttyEnabled>
                 <resourceRequestCpu></resourceRequestCpu>
                 <resourceRequestMemory></resourceRequestMemory>
                 <resourceLimitCpu></resourceLimitCpu>
                 <resourceLimitMemory></resourceLimitMemory>
                 <envVars>
                   <org.csanchez.jenkins.plugins.kubernetes.model.KeyValueEnvVar>
                     <key>DOCKER_HOST</key>
                     <value>localhost</value>
                   </org.csanchez.jenkins.plugins.kubernetes.model.KeyValueEnvVar>
                 </envVars>
                 <ports/>
                 <livenessProbe>
                   <execArgs></execArgs>
                   <timeoutSeconds>0</timeoutSeconds>
                   <initialDelaySeconds>0</initialDelaySeconds>
                   <failureThreshold>0</failureThreshold>
                   <periodSeconds>0</periodSeconds>
                   <successThreshold>0</successThreshold>
                 </livenessProbe>
               </org.csanchez.jenkins.plugins.kubernetes.ContainerTemplate>
               <org.csanchez.jenkins.plugins.kubernetes.ContainerTemplate>
                 <name>docker</name>
                 <image>docker:18.09-dind</image>
                 <privileged>true</privileged>
                 <alwaysPullImage>false</alwaysPullImage>
                 <workingDir>/home/jenkins/agent</workingDir>
                 <command></command>
                 <args></args>
                 <ttyEnabled>false</ttyEnabled>
                 <resourceRequestCpu></resourceRequestCpu>
                 <resourceRequestMemory></resourceRequestMemory>
                 <resourceLimitCpu></resourceLimitCpu>
                 <resourceLimitMemory></resourceLimitMemory>
                 <envVars/>
                 <ports/>
                 <livenessProbe>
                   <execArgs></execArgs>
                   <timeoutSeconds>0</timeoutSeconds>
                   <initialDelaySeconds>0</initialDelaySeconds>
                   <failureThreshold>0</failureThreshold>
                   <periodSeconds>0</periodSeconds>
                   <successThreshold>0</successThreshold>
                 </livenessProbe>
               </org.csanchez.jenkins.plugins.kubernetes.ContainerTemplate>
             </containers>
             <envVars/>
             <annotations/>
             <imagePullSecrets>
               <org.csanchez.jenkins.plugins.kubernetes.PodImagePullSecret>
                 <name>regcred</name>
               </org.csanchez.jenkins.plugins.kubernetes.PodImagePullSecret>
             </imagePullSecrets>
             <nodeProperties/>
             <yamlMergeStrategy class="org.csanchez.jenkins.plugins.kubernetes.pod.yaml.Overrides"/>
             <showRawYaml>true</showRawYaml>
             <podRetention class="org.csanchez.jenkins.plugins.kubernetes.pod.retention.Default"/>
           </org.csanchez.jenkins.plugins.kubernetes.PodTemplate>
         </templates>
         <serverUrl>https://xxx</serverUrl>
         <serverCertificate>----BEGIN CERTIFICATE----

----END CERTIFICATE----</serverCertificate>
      <skipTlsVerify>false</skipTlsVerify>
      <addMasterProxyEnvVars>false</addMasterProxyEnvVars>
      <capOnlyOnAlivePods>false</capOnlyOnAlivePods>
      <directConnection>false</directConnection>
      <jenkinsUrl>http:/xxx</jenkinsUrl>
      <credentialsId>k8s-jenkins-agents-sa-token</credentialsId>
      <containerCap>4</containerCap>
      <retentionTimeout>5</retentionTimeout>
      <connectTimeout>30</connectTimeout>
      <readTimeout>30</readTimeout>
      <podLabels>
        <org.csanchez.jenkins.plugins.kubernetes.PodLabel>
          <key>jenkins</key>
          <value>slave</value>
        </org.csanchez.jenkins.plugins.kubernetes.PodLabel>
      </podLabels>
      <usageRestricted>false</usageRestricted>
      <maxRequestsPerHost>32</maxRequestsPerHost>
      <waitForPodSec>1200</waitForPodSec>
      <podRetention class="org.csanchez.jenkins.plugins.kubernetes.pod.retention.Never"/>
    </org.csanchez.jenkins.plugins.kubernetes.KubernetesCloud>
  </clouds>
  <quietPeriod>0</quietPeriod>
  <scmCheckoutRetryCount>0</scmCheckoutRetryCount>
  <views>
    <hudson.model.AllView>
      <owner class="hudson" reference="../../.."/>
      <name>all</name>
      <filterExecutors>false</filterExecutors>
      <filterQueue>false</filterQueue>
      <properties class="hudson.model.View$PropertyList"/>
    </hudson.model.AllView>
  </views>
  <primaryView>all</primaryView>
  <slaveAgentPort>50000</slaveAgentPort>
  <label></label>
  <crumbIssuer class="hudson.security.csrf.DefaultCrumbIssuer">
    <excludeClientIPFromCrumb>false</excludeClientIPFromCrumb>
  </crumbIssuer>
  <nodeProperties/>
  <globalNodeProperties/>
  <noUsageStatistics>true</noUsageStatistics>
</hudson>#
 
Thanks