ASP.Net Parser Error Message: Unknown server tag cc1:ToolkitScriptManager

Hi harindaw,

You might have not registered the control in the page.

Or you had tagprefix as ajaxToolkit instead of cc1.

So verify it.

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>

Or use ScriptManager instead of ToolkitScriptManager as it is removed in latest version.

<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>