title: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger after updating log4j 1.2.17 to 2.13.0
body: <p>I am running Tomcat v9.0 server on a Java Eclipse project. Each time I run my application on the server I get this Problem Occured message: </p>
  
  <blockquote>
    <p>Server Tomcat v9.0 Server at localhost failed to start.</p>
  </blockquote>
  
  <p>This is the Console message that I get:</p>
  
  <pre><code>Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Server version name:   Apache Tomcat/9.0.30
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Server built:          Dec 7 2019 16:42:04 UTC
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Server version number: 9.0.30.0
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: OS Name:               Windows 10
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: OS Version:            10.0
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Architecture:          amd64
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Java Home:             C:\Program Files\Java\jre1.8.0_231
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: JVM Version:           1.8.0_231-b11
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: JVM Vendor:            Oracle Corporation
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: CATALINA_BASE:         C:\Users\msoph\Documents\Revature-Projects\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: CATALINA_HOME:         C:\Users\msoph\Desktop\apache-tomcat-9.0.30\apache-tomcat-9.0.30
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Command line argument: -Dcatalina.base=C:\Users\msoph\Documents\Revature-Projects\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Command line argument: -Dcatalina.home=C:\Users\msoph\Desktop\apache-tomcat-9.0.30\apache-tomcat-9.0.30
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Command line argument: -Dwtp.deploy=C:\Users\msoph\Documents\Revature-Projects\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Command line argument: -Djava.endorsed.dirs=C:\Users\msoph\Desktop\apache-tomcat-9.0.30\apache-tomcat-9.0.30\endorsed
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.VersionLoggerListener log
  INFO: Command line argument: -Dfile.encoding=Cp1252
  Jan 02, 2020 11:21:18 AM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
  INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [C:\Program Files\Java\jre1.8.0_231\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:/Program Files/Java/jre1.8.0_231/bin/server;C:/Program Files/Java/jre1.8.0_231/bin;C:/Program Files/Java/jre1.8.0_231/lib/amd64;C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\Program Files\Java\jdk-13.0.1\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Git\cmd;C:\ProgramData\chocolatey\bin;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.6.2\bin;C:\Program Files\PostgreSQL\12\bin;C:\Program Files\nodejs\;C:\Users\msoph\AppData\Local\Microsoft\WindowsApps;C:\Users\msoph\AppData\Local\Programs\Microsoft VS Code\bin;C:\Program Files\Java\jdk1.8.0_231\bin;C:\Users\msoph\AppData\Roaming\npm;C:\Users\msoph\Desktop\sts4Release;;.]
  Jan 02, 2020 11:21:18 AM org.apache.coyote.AbstractProtocol init
  INFO: Initializing ProtocolHandler ["http-nio-8080"]
  Jan 02, 2020 11:21:18 AM org.apache.coyote.AbstractProtocol init
  INFO: Initializing ProtocolHandler ["ajp-nio-8009"]
  Jan 02, 2020 11:21:18 AM org.apache.catalina.startup.Catalina load
  INFO: Server initialization in [798] milliseconds
  Jan 02, 2020 11:21:18 AM org.apache.catalina.core.StandardService startInternal
  INFO: Starting service [Catalina]
  Jan 02, 2020 11:21:18 AM org.apache.catalina.core.StandardEngine startInternal
  INFO: Starting Servlet engine: [Apache Tomcat/9.0.30]
  Jan 02, 2020 11:21:19 AM org.apache.catalina.core.ContainerBase startInternal
  SEVERE: A child container failed during start
  java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/project-1]]
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
      at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
      at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:343)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:474)
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/project-1]]
      at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
      at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
      ... 21 more
  Caused by: java.lang.NoClassDefFoundError: Lorg/apache/logging/log4j/Logger;
      at java.lang.Class.getDeclaredFields0(Native Method)
      at java.lang.Class.privateGetDeclaredFields(Unknown Source)
      at java.lang.Class.getDeclaredFields(Unknown Source)
      at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:110)
      at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:269)
      at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:137)
      at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:69)
      at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:330)
      at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:777)
      at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:301)
      at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5051)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      ... 27 more
  Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1365)
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
      ... 40 more
  
  Jan 02, 2020 11:21:19 AM org.apache.catalina.core.ContainerBase startInternal
  SEVERE: A child container failed during start
  java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:343)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:474)
  Caused by: org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:928)
      at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
      at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
      ... 13 more
  Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/project-1]]
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
      ... 21 more
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/project-1]]
      at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
      at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
      ... 21 more
  Caused by: java.lang.NoClassDefFoundError: Lorg/apache/logging/log4j/Logger;
      at java.lang.Class.getDeclaredFields0(Native Method)
      at java.lang.Class.privateGetDeclaredFields(Unknown Source)
      at java.lang.Class.getDeclaredFields(Unknown Source)
      at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:110)
      at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:269)
      at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:137)
      at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:69)
      at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:330)
      at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:777)
      at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:301)
      at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5051)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      ... 27 more
  Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1365)
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
      ... 40 more
  
  Jan 02, 2020 11:21:19 AM org.apache.catalina.startup.Catalina start
  SEVERE: The required Server component failed to start so Tomcat is unable to start.
  org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:928)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:343)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:474)
  Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
      ... 13 more
  Caused by: org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:928)
      at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
      at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
      ... 13 more
  Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/project-1]]
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:916)
      ... 21 more
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/project-1]]
      at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
      at java.util.concurrent.AbstractExecutorService.submit(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
      ... 21 more
  Caused by: java.lang.NoClassDefFoundError: Lorg/apache/logging/log4j/Logger;
      at java.lang.Class.getDeclaredFields0(Native Method)
      at java.lang.Class.privateGetDeclaredFields(Unknown Source)
      at java.lang.Class.getDeclaredFields(Unknown Source)
      at org.apache.catalina.util.Introspection.getDeclaredFields(Introspection.java:110)
      at org.apache.catalina.startup.WebAnnotationSet.loadFieldsAnnotation(WebAnnotationSet.java:269)
      at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:137)
      at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:69)
      at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:330)
      at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:777)
      at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:301)
      at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5051)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
      ... 27 more
  Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1365)
      at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
      ... 40 more
  
  Jan 02, 2020 11:21:19 AM org.apache.coyote.AbstractProtocol pause
  INFO: Pausing ProtocolHandler ["http-nio-8080"]
  Jan 02, 2020 11:21:19 AM org.apache.coyote.AbstractProtocol pause
  INFO: Pausing ProtocolHandler ["ajp-nio-8009"]
  Jan 02, 2020 11:21:19 AM org.apache.catalina.core.StandardService stopInternal
  INFO: Stopping service [Catalina]
  Jan 02, 2020 11:21:19 AM org.apache.coyote.AbstractProtocol destroy
  INFO: Destroying ProtocolHandler ["http-nio-8080"]
  Jan 02, 2020 11:21:19 AM org.apache.coyote.AbstractProtocol destroy
  INFO: Destroying ProtocolHandler ["ajp-nio-8009"]
  </code></pre>
  
  <p>I assume that there is an issue with my logger.  I was originally using log4j v1.2.17 and then I thought to upgrade to the most recent version of log4j which is v2.13.0. </p>
  
  <p>This is what my <code>log4j2.properties file</code> looks like:</p>
  
  <pre><code>status = error
  name = PropertiesConfig
  
  #Make sure to change log file path as per your need
  property.filename = C:\\Users\\msoph\\Documents\\Revature-Projects\\project-1\\logs\\log.txt
  filters = threshold
  
  filter.threshold.type = ThresholdFilter
  filter.threshold.level = debug
  
  appenders = rolling
  
  appender.rolling.type = RollingFile
  appender.rolling.name = RollingFile
  appender.rolling.fileName = ${filename}
  appender.rolling.filePattern = debug-backup-%d{MM-dd-yy-HH-mm-ss}-%i.log.gz
  appender.rolling.layout.type = PatternLayout
  appender.rolling.layout.pattern = %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
  appender.rolling.policies.type = Policies
  appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
  appender.rolling.policies.time.interval = 1
  appender.rolling.policies.time.modulate = true
  appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
  appender.rolling.policies.size.size=10MB
  appender.rolling.strategy.type = DefaultRolloverStrategy
  appender.rolling.strategy.max = 20
  
  loggers = rolling
  
  #package structure
  
  logger.rolling.name = com.revature
  logger.rolling.level = debug
  logger.rolling.additivity = false
  logger.rolling.appenderRef.rolling.ref = RollingFile
  </code></pre>
  
  <p>What is the root cause of this Server error, and how can I fix this? Thank You.</p>