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Value must not be null for controls and behaviors

Posted By:      Posted Date: September 07, 2010    Points: 0   Category :ASP.Net
Best all, Any idea what the problem is with this script warning? Value must not be null for controls and behaviors Thanks  

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Error: Sys.ArgumentException: Value must not be null for Controls and Behaviors.


I have a fairly complex web application that loads UserControls dynamically based on what section the user selects.


The UserControls contain RoundedCornersExtender and CollapsiblePanelExtender controls as well as UpdatePanel controls.
After updating to the latest AJAX Framework Beta, I am now seeing the following JavaScript error:

Line: 1961
Char: 23
Error: Sys.ArgumentException: Value must not be null for Controls and Behaviors.
Parameter name: element
Code: 0

Has anyone else seen this issue and does anyone have any suggestions?

Nested controls in UserControl return null (FindControl)

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Masterpage + UpdatePanel + Formview + EditItemTemplate = Null controls

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RowCommand returns null value for controls which are not binded to Gridview source


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all basic windows controls,wpf controls,silverlight application

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