title: ClassNotFoundException when accessing applet, but only for some
body: <p>I recently got an email from a customer saying that they were getting errors on one of our web apps.  We have a date/time picker applet that's used throughout this app and it's not displaying for this user.  The tag in the HTML page is:</p>
  
  <pre><code>&lt;APPLET CODE="com.enerwise.applet.datetime.DateTimeSelector" WIDTH=250 HEIGHT=30  codebase="/japps" name="app_date_start" align="middle" archive="DateTimeSelector.jar,VisualSoftJBCalendar.jar"&gt;
  &lt;PARAM NAME="locale" VALUE= "en_US" &gt;&lt;PARAM NAME="interval" VALUE= "-1" &gt;
  &lt;/APPLET&gt;
  </code></pre>
  
  <p>The error he's reporting is <code>ClassNotFoundException</code> in <code>com.enerwise.applet.datetime.DateTimeSelector</code>.  He's tried accessing the page from several different computers in his office and gets the same error.  He has Java 1.7 installed (the applet is old; likely compiled with 1.4) and has tried from Win XP/IE8 and Win 7/IE9 machines.  I've tried it from a Win XP/IE8 and a Win 7/IE9 machine with java 1.7 and had no problem.</p>
  
  <p>He's the only customer (that I know of) having this problem.  I'm stumped!  I suggested that he try from a computer that's NOT on his work network; I haven't gotten a reply yet.</p>
  
  <p>Can anyone suggest something to check on his system?  I found another <a href="https://stackoverflow.com/questions/7368735/classnotfoundexception-when-loading-applet-on-some-computers">thread</a> where the problem was the users proxy setting in the Java Console.  I'll have him check that as well.</p>
  
  <p>Is it possible that his company's IT dept. Made a change to their security and it's blocking applets/jar files?  Would he get a <code>ClassNotFound</code> message in that case?</p>