[Solved] System.InvalidOperationException: A control with ID lnkView could not be found for the trigger

Event not firing and getting error inside UpdatePanel I am trying to call using Triggers but no result.

Error:

System.InvalidOperationException: A control with ID lnkView could not be found for the trigger in

<asp:UpdatePanel ID="udpanel" runat="server">
    <ContentTemplate>
        <asp:GridView ID="TransactionalData_gv" runat="server" AutoGenerateColumns="False"
            CssClass="gridview-tabl" Style="border: solid 1px #d8d8d8;" EmptyDataText="No Record to Display !"
            AllowPaging="true" PageSize="10" Width="100%" OnRowDataBound="OnRowDataBound"
            EnableViewState="false">
            <Columns>
                <asp:TemplateField HeaderStyle-HorizontalAlign="Center" HeaderText="APPROVE" HeaderStyle-Width="15%" ItemStyle-HorizontalAlign="Center">

                    <ItemTemplate>
                        <asp:ImageButton ID="imgAppr" Height="30px" Width="30px" ImageUrl="~/distribution/img/APPROVE.jpg"
                            OnClick="OnApproveSingle" OnClientClick="ApproveSingleClient()" runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="REJECT" ItemStyle-HorizontalAlign="Center">
                    <ItemTemplate>
                        <asp:ImageButton ID="imgReject" Height="30px" Width="30px" ImageUrl="~/distribution/img/REJECT.jpg"
                            OnClick="OnRejectSingle" OnClientClick="RejectSingleClient()" runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="REJECT REMARK">
                    <ItemTemplate>
                        <asp:TextBox ID="txtRemark" TextMode="MultiLine" Text='<%# Eval("REMARK") %>' runat="server"></asp:TextBox>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:BoundField DataField="STATUS" HeaderText="STATUS" />
                <asp:BoundField DataField="FILE_NAME" HeaderText="FILE NAME" />
                <asp:BoundField DataField="INITIATED_BY" HeaderText="CREATOR" />
                <asp:BoundField DataField="UPLOAD_DATE" HeaderText="UPLOAD DATE" />
                <asp:BoundField DataField="MODIFIED_DATE" HeaderText="MODIFIED DATE" />
                <asp:BoundField DataField="TRAN_MONTH" HeaderText="TRAN MONTH" />
                <asp:TemplateField HeaderText="View" ItemStyle-HorizontalAlign="Center">
                    <ItemTemplate>
                        <asp:LinkButton ID="lnkView" Text="View" runat="server" OnClick="OnView" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="REOPEN" ItemStyle-HorizontalAlign="Center">
                    <ItemTemplate>
                        <asp:LinkButton Text="REOPEN" runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
            <HeaderStyle BackColor="#20c4b5" Font-Bold="True" Font-Size="Medium" HorizontalAlign="Justify"
                ForeColor="White" />
            <RowStyle Font-Size="Small" HorizontalAlign="Justify" />
        </asp:GridView>
    </ContentTemplate>
    <Triggers>
        <asp:AsyncPostBackTrigger ControlID="TransactionalData_gv" EventName="PageIndexChanging" />
        <asp:AsyncPostBackTrigger ControlID="lnkView" EventName="OnView" />
        <%--   <asp:AsyncPostBackTrigger ControlID="Userlist_gv" EventName="RowDataBound" />--%>
    </Triggers>
</asp:UpdatePanel>