title: Firebird error message "Unsuccessful execution caused by a system error that precludes successful execution of subsequent statements"
body: <p>My application generates sometimes this kind of errors when accessing Firebird database:</p>
  
  <blockquote>
    <p>Unsuccessful execution caused by a system error that precludes
    successful execution of subsequent statements GDS Code: 335544726 -
    SQL Code: -902 - Error Code: 406'</p>
  </blockquote>
  
  <p>What could be the problem? Is there any way to debug this?</p>
  
  <p>I'm running Firebird 2.5.1 on Windows 7. There are at least kinterbasdb with Python and UIB components with Delphi in use.</p>