title: "Sys.WebForms.PageRequestManagerServerErrorException: status code: 500"
body: <p>I am using an asp.net text box inside ajax update panel. If I enter &amp;#  in the textbox and press Save Button , it gives a javascript error </p>
  
  <blockquote>
    <p>Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 500</p>
  </blockquote>
  
  <p>Please help me why this error appears?</p>
  
  <p><img src="https://i.stack.imgur.com/lbDAK.png" alt="enter image description here"></p>