Asp.net Response.Redirect

I am using response.redirect after iam deleting a particular user to have grid populated with latest values.. but it giving me error lblError.Text=Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack.

because of this error iam not getting confirmation of deletion any help will be appreciated

code:- if (chk.Checked == true) {

                        isDeleted=oFTE.DeleteUserRoleMapDetails(row.Cells[1].Text);
                        if (isDeleted == 0)
                        {
                            lblError.Visible = true;
                            lblError.ForeColor = System.Drawing.Color.Red;
                            lblError.Text = "User Role Map deletion failed.";
                        }
                        else if (isDeleted == 1)
                        {
                            lblError.Visible = true;
                            lblError.ForeColor = System.Drawing.Color.Red;                                
                            //Response.Redirect("userRoleMap.aspx");
                            Session["Msg"] = "User Role Map deleted successfully.";
                            Response.Redirect("userRoleMap.aspx",false);

                           //lblError.Text = "User Role Map deleted successfully.";                                 
                            break;
                        }                                                     
                    }

                    if (iRowCount == gridViewResults.Rows.Count)
                    {
                        lblError.Visible = true;
                        lblError.ForeColor = System.Drawing.Color.Red;
                        lblError.Text = "Please select 开发者_StackOverflowa row to delete.";
                    }
                }
            }
        }
        catch (Exception ex)
        {
            lblError.Visible = true;
            lblError.ForeColor = System.Drawing.Color.Red;
            lblError.Text = ex.Message.ToString();
        }           
    }      

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blError.Text=Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack.

Is only shown in the Locals/Watch windows when you've paused the debugger inside a native call. It's not an actual error preventing your page from loading. Perhaps, the problem is that you've set a breakpoint in your code and the request is timing out from the browser before you've resumed execution?

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The message is coming from the debugger. Run your application without the debugger to see the real error.