I have a development and production version of a .NET 4.0 web project that are nearly identical outside of some config options. Both have App_Themes/Default/Default.skin file that contain, among other server controls (Button, DataGrid, TextBox, etc), a
skin for a ModalPopupExtender (see below). "cc1" is added in the <pages><controls> section of the web.config of both. The MasterPage contains a ScriptManager in both. Everything seems to be in place in both, but when I build the prod project it fails with
the error, "The control type 'AjaxControlToolkit.ModalPopupExtender' cannot be themed.". There are no other errors and the dev project builds and runs without any errors. Can anyone suggest why it would be working in one and not the other or where to look
for a solution?
<cc1:ModalPopupExtender runat="server" BackgroundCssClass="x-modalBackground" DropShadow="true"></cc1:ModalPopupExtender>