title: Cannot reference custom event from web.config
body: <p>I've written a custom event <code>MyWebErrorEvent</code> derived from <code>WebErrorEvent</code> located in the App_Code folder of my ASP.NET 2.0 Web Site Project.  The class <code>MyWebErrorEvent</code> is not contained within a namespace.  I've put the following into my web.config file:</p>
  
  <pre><code>&lt;configuration&gt;
    &lt;system.web&gt;
      &lt;healthMonitoring&gt;
        &lt;eventMappings&gt;
          &lt;add name="Event1" startEventCode="0" endEventCode="2147483647" type="MyWebErrorEvent"/&gt;
        &lt;/eventMappings&gt;
      &lt;/healthMonitoring&gt;
    &lt;/system.web&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>At compile time and run time I get the following error:</p>
  
  <pre><code>Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
  
  Parser Error Message: Could not load type 'MyWebErrorEvent'.
  
  Source Error: 
  
  Line 16: &lt;healthMonitoring&gt;
  Line 17: &lt;eventMappings&gt;
  Line 18: &lt;add name="Event1" startEventCode="0" endEventCode="2147483647" type="MyWebErrorEvent"/&gt;
  Line 19: &lt;/eventMappings&gt;
  Line 20: &lt;/healthMonitoring&gt;
  </code></pre>
  
  <p>The class MyWebErrorEvent does indeed compile without errors.  Anyone know how to fix this?</p>
  
  <p><strong>EDIT:</strong> <a href="http://msdn.microsoft.com/en-us/library/bb398933.aspx" rel="nofollow noreferrer"><a href="http://msdn.microsoft.com/en-us/library/bb398933.aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/bb398933.aspx</a></a> says that this should work for custom events.  A quote:</p>
  
  <blockquote>
    <p>Add the assembly that contains the custom Web event implementation to the Bin subdirectory of the ASP.NET application. Alternatively, you can add the event source code file to the App_Code subdirectory.</p>
  </blockquote>
  
  <p>However it also says this will not work for custom event providers:</p>
  
  <blockquote>
    <p>Put the assembly that contains the custom provider implementation in the application's Bin subdirectory. You cannot put the provider source code file in the App_Code subdirectory, because the health monitoring system is configured and created before any code files in the App_Code subdirectory are compiled. </p>
  </blockquote>
  
  <p>I'm guessing the documentation is actually incorrect about custom events and they must go into a assymbly distinct from the web site.</p>