JavaScript runtime error: 'WebForm_InitCallback' is undefined

4 posts, 0 answers
  1. Andrew Dorfman
    Andrew Dorfman avatar
    6 posts
    Member since:
    Sep 2008

    Posted 27 Aug 2013 Link to this post

    When running my ASP.NET webforms app in the Visual Studio 2012 debugger using IIS Express and a localhost URL I'm getting the following error:

    JavaScript runtime error: 'WebForm_InitCallback' is undefined

    however when I deploy the app and run under IIS I do not get the error.  I've tried everything and can't resolve this.  Any suggestions?

  2. Shinu
    Shinu avatar
    17764 posts
    Member since:
    Mar 2007

    Posted 27 Aug 2013 Link to this post

    Hi Andrew,

    From what you have provided as an information it appears that the problem is related to the web resources. Please refer to the following help article showing how to troubleshoot this kind of problems.

    Hope this helps,
  3. Dirk
    Dirk avatar
    8 posts
    Member since:
    Aug 2011

    Posted 18 Sep 2013 Link to this post

    I encountrered the same issue, my local project started throwing JS errors (after a windows 8 reinstall) like you mentioned and failed to load WebResource files (css mostly). On IIS these errors did not occur. After A LOT of searching (internet was not really helpful) I found that adding a RadStylesheetmanager to my (master)page resolved all my issues.

    <head runat="server">
        <telerik:RadStyleSheetManager id="RadStyleSheetManager1" runat="server" />

    Dont ask me why, all I know is I can make the errors appear/dissapear by resp. removing/adding this element, at this time I'm glad I finally solved this and I'll settle for a solution with no explanation.
  4. Aniello
    Aniello avatar
    1 posts
    Member since:
    Oct 2013

    Posted 05 Oct 2013 Link to this post


    i solved this problem simply emptying the cache browser.

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