SYSK 240: AJAX.NET – Resolution for Sys.ScriptLoadFailedException when Opening Login page

Are you getting Microsoft JScript runtime error: Sys.ScriptLoadFailedException:

The script '/YourSiteName/ScriptResource.axd?d=ebUIu-RsatQBXvExgP5y3pvOqX2PbIJ6uav4Avk4QzmounX74siwLINKKPmlFz54oTPVrGJa4XpgCYiosTExfEdJoHleHTQaH7TE19A6Hqg1&t=632986009464531250' could not be loaded or does not contain the Sys.Application.notifyScriptLoaded() callback


Is your authentication mode = “Forms”?  Does it happen when you’re loading your login page?


To resolve the problem, add:

<location path="ScriptResource.axd">



                        <allow users="*"/>





to your web.config.


Comments (8)

  1. mahantesh says:


    i am getting the same error , but authentication node is not form, please let me know reason

  2. mahantesh says:


    i tried with it ,but it is givving error, <asp:UpdatePanel is undefined

  3. irenake says:

    Sounds like you’re missing things in web.config.  Consider creating a new AJAX project, and compare your web.config with that one.  Also, if you only get this in design view, just ignore it…  it’s a known problem when using master page.

  4. I am able to run the Application fine where I have used Ajax 1.0 beta 2 until postback.

    After the PostBack  It does not Working. Again the Application Start working if I Removes all the ScriptResource.axd files from the Temporary internet Folder.

    Can anyone please come forward to let me know any solutions or the reason for this Problem.

    Thanks & Regards,


  5. Daniel says:

    I am having the same problem when i dynamically add an accordion control to a page.

  6. Sathisha B N says:


    i have form which has the update pannel and the update progress

    this aspx i am calling this aspx page under frame

    i am getting the following error

    Microsoft JScript runtime error: ‘Sys’ is undefined

  7. irenake says:

    Sounds like something is missing in web.config.  Did you ‘Ajaxify’ an older project?  Try creating a brand new ASP.NET AJAX-Enable Web Site, add an update panel and see if you get any errors…

  8. srinandan1 says:

    I am getting the same error but not a form authentication.

    the page where i am getting error is a content page having the timer and update panel.



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