As far as I remember, this error has to do with the ViewState. Try disabling ViewState for these new controls. That's one of the problems with adding new controls in run-time - you may get this error which is very hard to deal with.
>I created a user control that has 2 RadioButtonLists and 2 DropDownLists. One set of RadioButtonLists enables one of the DropDownLists. If I drop the control onto a page and run it, it works fine.
>
>However, we're going to end up with 50+ controls, so I'm adding them to the page at runtime, like this:
>
>
>Control control = LoadControl(ControlName);
>PlaceHolder1.Controls.Add(control);
>
>
>
>When I click either of the RadioButtonLists or DropDownLists I get
>
>
>---------------------------
>Microsoft Internet Explorer
>---------------------------
>Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server
>could not be parsed. Common causes for this error are when the response is modified by calls to
>Response.Write(), response filters, HttpModules, or server trace is enabled.
>
>Details: Error parsing near '<!DOCTYPE html P'.
>---------------------------
>OK
>---------------------------
>
>
>I Googled it and found this,
http://weblogs.asp.net/leftslipper/archive/2007/02/26/sys-webforms-pagerequestmanagerparsererrorexception-what-it-is-and-how-to-avoid-it.aspx, but this is all greek to me. I have no clue what's wrong
>or how to fix it.
>
>Help!
If it's not broken, fix it until it is.
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