Click here to Skip to main content
65,938 articles
CodeProject is changing. Read more.
Articles / web / HTML

ASP.NET ScriptManager Error: this._forum is not a object

5.00/5 (1 vote)
16 Apr 2012CPOL 7.3K  
Little-Big bug from ScriptManager

I happened a few times to receive this error on an ASP.NET page that contains a ScriptManager and a link to a JavaScript file inside the Head tag on the page, like this:

XML
[...]
<head runat="server">
    <script type="text/javascript" src="../Scripts/barcode.js" />
</head>
<body>
    <form id="form1" runat="server">
    <asp:ScriptManager ID="ScriptManager1" runat="server" />
    <div>
    [...]

Apparently the code is without errors, but running the page in debug mode, you receive an error like this:

Image 1

Microsoft Javascript: object needed

By clicking on the button "Stop", I’m going to try to understand what might have happened, and I realize that the object "_form" of the page does not exist, or is "null".

this._form is NULL

this._form is NULL

Needless to tell you how long I spent trying to figure out what could have happened, and where could be a possible error, of course without success.

After a meticulous search on the internet, I finally found an article that enlightened and saved me. It seems to be a small bug of ScriptManager object, which misinterprets the tag <script /> without explicit locking.

It was sufficient to change the tag and use the canonical syntax to solve it all:

XML
<head runat="server">
    <script type="text/javascript" src="../Scripts/barcode.js" >
    </script>
</head>

End of the ordeal.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)