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Input string was not in a correct format


I am developing a web application using ASP.NET. I hosted the application in IIS and I opened it in Internet explorer and logged in, it works fine. Then i tried in chrome and logged in, That worked like a charm. Then i came to fire fox, I tried to log in. but its not logging in. The error i am getting is "Input string was not in a correct format" why is this happening???

Additional System Details

Installed Plug-ins

  • Shockwave Flash 11.5 r502
  • Adobe PDF Plug-In For Firefox and Netscape "9.5.3"
  • Google Update
  • 5.1.10411.0


  • User Agent: Mozilla/5.0 (Windows NT 6.1; rv:19.0) Gecko/20100101 Firefox/19.0

More Information

  • Top 10 Contributor
2365 solutions 20922 answers

Is that a message generated by ASP.Net on the server, or by your own code?

You can observe what Firefox is sending to the server using the Firebug add-on. Click the bug icon to open the pane, click the Net tab, then reload your page and try to submit the form. For the POST request check the post body and parameters. Anything unusual?

If it's not an HTTPS connection, you can use an external proxy like Fiddler to compare the traffic from the 3 browsers.

Firebug: https://addons.mozilla.org/en-US/firefox/addon/firebug/

Fiddler: http://www.fiddler2.com/