Hi,
As Soon as i add the Tag ID in the definition of an ID panel, i have this error : System.Web.UI.Updatepanel type not definied.
ie:
<asp:UpdatePanel ID="Up_Panel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="False">
<ContentTemplate><./ContentTemplate>
</asp:UpdatePanel>
The version Of visual Studio is 2013 up 4 and Sharepoint 2013.
can Anyone help me???