title: Why can't Flash CS3 find the MovieClip base class even after classpath is set (AS3)?
body: <p>Tearing my hair out.
  I created an as3 class - blah.Foo, which extends MovieClip.
  it is not in a package, cos Flash CS3 complained about nested packages, so it's a 'bare' class.</p>
  
  <p>And yes it's nested in <strong>myproj/as/blah/Foo.as</strong>
  And yes, it imports flash.display.MovieClip at the top of the file.</p>
  
  <p>I also have <strong>myproj/fla/main.fla</strong>.
  main.fla is set to publish as AS3 against flash player 9.
  main.fla has classpath which includes myproj/as/</p>
  
  <p>on frame1 scene1 in main.fla:</p>
  
  <pre><code>import blah.Foo;
  var myfoo:Foo = new Foo();
  stop();
  </code></pre>
  
  <p>compiler dies at class definition of Foo in Foo.as:</p>
  
  <pre><code>import flash.display.MovieClip;
  class blah.Foo extends MovieClip //&lt;=== dies here
  {
      //whatever...
  }
  </code></pre>
  
  <p>It complains that:
  <strong>"1017: The definition of base class MovieClip was not found".</strong></p>
  
  <p>Someone please help! How can it not find one of the most basic classes in AS3?!!</p>