title: Zend_Session uncaught exception
body: <p>So I have this in my index.php:</p>
  
  <pre><code>Zend_Session::start();
  </code></pre>
  
  <p>Then in one of my controllers in the init method I do:</p>
  
  <pre><code>if (false === isset($this-&gt;defaultNamespace-&gt;tree)) {
      $this-&gt;defaultNamespace-&gt;tree = array();
  }
  </code></pre>
  
  <p>Which still works. But then in action in the same controller I write this:</p>
  
  <pre><code>unset($this-&gt;defaultNamespace-&gt;tree); // I tried commenting this line
  $this-&gt;defaultNamespace-&gt;tree = $this-&gt;tree;
  </code></pre>
  
  <p>And I get an exception like this:</p>
  
  <pre><code>&lt;br /&gt;
  &lt;b&gt;Fatal error&lt;/b&gt;:  Uncaught exception 'Zend_Session_Exception' with message 'Zend_Session::start() - D:\data\o\WebProjects\elearning\public\index.php(Line:22): Error #2 include() [&amp;lt;a href='function.include'&amp;gt;function.include&amp;lt;/a&amp;gt;]: Failed opening 'SlideQuestion.php' for inclusion (include_path='D:\data\o\WebProjects\elearning/../../library;D:\data\o\WebProjects\elearning/application/../library;.;C:\php\pear;D:\data\o\WebLib\ZendFramework\library;') Array' in D:\data\o\WebLib\ZendFramework\library\Zend\Session.php:493
  Stack trace:
  #0 D:\data\o\WebProjects\elearning\public\index.php(26): Zend_Session::start()
  #1 {main}
    thrown in &lt;b&gt;D:\data\o\WebLib\ZendFramework\library\Zend\Session.php&lt;/b&gt; on line &lt;b&gt;493&lt;/b&gt;&lt;br /&gt;
  </code></pre>
  
  <p>The $this->tree is a property contains an array with some objects in it.</p>