Hello

I am searching for a solution for over 20 days, The problem appears only when I load Web Users Controls as Dynamic in the Default.aspx,

If I add the by drag it into the page as Static , there is no problem.

This is how the code in default.aspx for static (fixed)
Code:
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <uc1:WebControl1 runat="server" ID="WebControl" />
</asp:Content>


I have a Masterpage and Default.aspx and many web controls,

I add ScriptManager in the MasterPage as following

Code:
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true"></asp:ScriptManager>
<div>
<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
                                         
</asp:ContentPlaceHolder>
</div>
</form>
and I added the Following in the Default.aspx Page

Code:
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
    
</asp:Content>
    
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
 
</asp:Content>
I used the following code in the Default.aspx.cs (Code Behind) File to load the pages based on passed parameters

HTML Code:
[CODE] // find the place holder
ContentPlaceHolder mainContent = (ContentPlaceHolder)Master.FindControl("ContentPlaceHolder1");
 // load the control
//page name is the webcontrol name and its source
Control MyControl = (Control)LoadControl(pagename);
// add the control
mainContent.Controls.Add(MyControl);[/CODE]
I used the following code in the Webcontrol.ascx

Code:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
                        <ContentTemplate>
some controls such as datagrid, buttons and dropdowns

Code:
 </ContentTemplate>
                    </asp:UpdatePanel>

and in the code behind 

 if (IsPostBack == true)
        {
 
            ScriptManager.GetCurrent(Page).RegisterPostBackControl(Submitbtn);
        }
I hope I can find solution like everytime.

Thanks