title: Missing class: org.apache.commons.lang.exception.NestableException
body: <p>I am following <a href="http://commons.apache.org/proper/commons-configuration/userguide/howto_properties.html#Special_Characters_and_Escaping" rel="nofollow">an online example</a> to read information from a basic properties file. As I started to implement the code I keep getting the following error at the top of the class. </p>
  
  <blockquote>
    <p><code>The type org.apache.commons.lang.exception.NestableException cannot be resolved. It is indirectly referenced from required .class files</code></p>
  </blockquote>
  
  <p>I have sought to resolve the error by downloading the apache commons lang package from <a href="http://commons.apache.org/proper/commons-lang/" rel="nofollow">this page</a> and including it in my project properties, but this did not resolve the issue. </p>
  
  <p>Can someone please give me some insight on why this error is being thrown, and how to resolve it. </p>