title: java.lang.NoClassDefFoundError: org/openqa/selenium/remote/SessionNotFoundException
body: <p>I am using Firefox 45.0 and Dependency added in <code>pom.xml</code> is
  <code>selenium-firefox-driver 2.53.0</code>.</p>
  
  <pre><code>java.lang.NoClassDefFoundError: org/openqa/selenium/remote/SessionNotFoundException
      at TestFIles_MDM.Test_Authn.setup(Test_Authn.java:27)
  </code></pre>
  
  <p>Error is coming for both Firefox and Chrome.</p>
  
  <p>How can I resolve it, it was working last week.</p>