title: SCRIPT5022: Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format
body: <p>On IE10, when I click the login button I see the following error in the console:
  SCRIPT5022: Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format. 
  ScriptResource.axd, line 939 character 13</p>
  
  <p>I added some server-side logging, but the page is never sent, so it seems a client side issue.</p>
  
  <p>This behavior does not occur in IE8, Firefox OR chrome, there it works fine.</p>