title: Eclipse not showing classes from an external JAR file
body: <p>I am currently trying to develop a plugin using the Bukkit API in Eclipse. However, it seems I cannot import specific classes from the API jar file. If I open the jar file up and look in the list of classes, the classes are there. However, eclipse will not accept import of those classes into my own classes. It shows an error denoting:</p>
  
  <blockquote>
    <p>[classname] cannot be resolved to a type</p>
  </blockquote>
  
  <p>I see no reason why the class should not be accepted. Other classes from the same package are imported properly. Other developers using the Bukkit API do not have this problem (I specifically asked).</p>
  
  <p>Picture showing error:</p>
  
  <p><img src="https://i.stack.imgur.com/tmLuN.png" alt=""></p>
  
  <p>The class <code>EntityEnderman</code> is in the same package as the class <code>PathfinderGoalEndermanPickupBlock</code>. But <code>EntityEnderman</code> is properly imported, <code>PathfinderGoalEndermanPickupBlock</code> is not. </p>
  
  <p>Here's a picture showing what happens if I click the <em>Fix Project Setup</em> option:</p>
  
  <p><img src="https://i.stack.imgur.com/90cfy.png" alt=""></p>
  
  <p>I have already tried to manually edit the build path.</p>
  
  <p>Picture showing proof that the class is really added to the build path of the project:</p>
  
  <p><img src="https://i.stack.imgur.com/81zh5.png" alt=""></p>
  
  <p><strong>Why would this happen, and how can I fix it?</strong></p>
  
  <p>I am using the 1.8 version of the API found at spigotmc.org. I am using the newest eclipse available from the Linux Mint repository (Eclipse 3.8). This same error occurs in Netbeans 8, however.</p>