title: Error "There is no source code available for the current location."
body: <p>I added the AjaxControlToolKit's sample DLL file as a reference to my web application. I used Mask text boxes on my pages.</p>
  
  <p>While debugging the application, it first asked me to open MaskedEditExtender.cs file. So I just search it from my physical location and copied it in the Bin folder of the solution. Well ... now it is not asking for opening that file. But while debugging, after the content page, it debugs the master page as expected, but after just finishing debug of the master page, the debugger traverses to the MaskedEditExtender.cs file...</p>
  
  <p>That is not much of an issue. That's fine (I am curious why this happening), but while debugging the MaskedEditExtender.cs file, it pop ups the message</p>
  
  <blockquote>
    <p>There is no source code available for the current location."</p>
  </blockquote>
  
  <p>with two buttons, "OK" and "Disassembly". What is this error? Why is it arriving? How do I avoid it?</p>