Unable to start tomcat 7: Caused by: java.lang.NoClassDefFoundError
<p>My web project was running fine till yesterday however today when I start my tomcat server 7 it fails to start with below error in eclipse:</p>

<pre><code>Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/CiscoQA_Automation_Framework]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 7 more
Caused by: java.lang.NoClassDefFoundError: org/apache/logging/log4j/Logger
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.catalina.startup.WebappServiceLoader.loadServices(WebappServiceLoader.java:192)
at org.apache.catalina.startup.WebappServiceLoader.load(WebappServiceLoader.java:157)
at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1577)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1281)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5419)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.Logger
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1722)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1573)
... 19 more
</code></pre>

<p>After referring <a href="https://stackoverflow.com/questions/10556201/java-lang-classnotfoundexception-httpservletrequest">here</a> and few other links I have cleaned up WEB-INF/lib and classpath and then added "log4j-web-2.3.jar" and "log4j-1.2.17.jar" in both WEB-INF/lib and class path. I have tried cleaning up the project and tomcat working directory as well nothing worked.</p>

<pre><code>&lt;Server port="8005" shutdown="SHUTDOWN"&gt;
  &lt;Listener className="org.apache.catalina.startup.VersionLoggerListener"/&gt;
  &lt;!-- Security listener. Documentation at /docs/config/listeners.html
  &lt;Listener className="org.apache.catalina.security.SecurityListener" /&gt;
  --&gt;
  &lt;!--APR library loader. Documentation at /docs/apr.html --&gt;
  &lt;Listener SSLEngine="on"          className="org.apache.catalina.core.AprLifecycleListener"/&gt;
  &lt;!--Initialize Jasper prior to webapps are loaded. Documentation at /docs/jasper-howto.html --&gt;
  &lt;Listener className="org.apache.catalina.core.JasperListener"/&gt;
  &lt;!-- Prevent memory leaks due to use of particular java/javax APIs--&gt;
  &lt;Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener"/&gt;
  &lt;Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener"/&gt;
  &lt;Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener"/&gt;
</code></pre>