What causes the 'Cannot unregister UpdatePanel' error?

Question

I\'ve got a UserControl that contains an UpdatePanel. When I put that on a page, it throws the following error:

Cannot unregister UpdatePanel with ID

Answer 1

I had this happen once before. To fix it, I just deleted it and then re-created it and the problem went away.

Answer 2

This error occurs when the Controls collection in which the UpdatePanel is resided is cleared using the Clear method, or when the specific UpdatePanel is removed using the Remove method.

A trigger for these methods could be the implementation of the CreateChildControls method for the control contains the UpdatePanel. Usually, you call Controls.Clear() in the top of this method, to start with a clean slate if this method is called repeatedly.

Answer 3

Have you tried including a ScriptManagerProxy in the user control?

Answer 4

This is a bit of a long shot, but I've had experiences with the AJAX extensions, specifically with the update panel, in which errors thrown by child controls were manifesting themselves as a different error thrown by the update panel. I did see a reference to this specific error being thrown due to an error in a child control:

http://msmvps.com/blogs/shareblog/archive/2009/03/11/cannot-unregister-updatepanel-with-id-since-it-was-not-registered-with-the-scriptmanager-and-moss.aspx

Not sure if this is the case for you or not, but I've spent many hours chasing down the wrong errors because of this.

Answer 5

Try to remove the scriptproxy of UserControl. In this case you only have a ScriptManager on your page.

Answer 6

Are you moving controls about in code? If so take a look here and see if this solves your problem.