title: An exception of type 'System.NullReferenceException' occured in mscaptcha.dll but was not handled in user code
body: <p>I am using MS Captcha but stuck with this error. Why this error comes as it may be Timeout issue but I disabled maxtimeout and mintimeout to value 0. </p>
  
  <p>Would Some one describe how MS Captcha is working exactly.</p>
  
  <p>Here are the aspx code and Code Behind Error.</p>
  
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