title: Failed to find ij package
body: <p>today, I've tried to run my ImageJ plugin My_S but ImageJ always gives off the following Warning: </p>
  
  <pre><code> Plugin or class not found: "My_S"
   (java.lang.ClassNotFoundException: My_S)
  </code></pre>
  
  <p>I think that it kind of skips the compiling step, because there is no My_S.class file in the plugin folder. 
  This is a little weird, because it worked before (I tried it for one plugin only though).
  Then I tried to compile it from the console with</p>
  
  <pre><code>javac My_S.java
  </code></pre>
  
  <p>which gives off the following qarning:</p>
  
  <pre><code>My_S.java:1: package ij does not exist
  import ij.*;
  ^
  </code></pre>
  
  <p>So, I tried to re-install it (my system is linux mint btw) but IJ still shows off the same behavior.... : / 
  Are there any suggestions on how to solve this problem? (I hope this is the right place to ask this question)</p>
  
  <p>Thanks</p>