Original Record Isn’t Reloading After Update [duplicate]

I have a customers page with an edit button. I can click the edit button, it loads the customers_edit.php page and I can edit the customer. When I click save, it grabs the customerID as the updateID and attempts to reload the customer_edit page with the updateID in the address bar but it gives me a “is currently unable to handle this request. HTTP ERROR 500” page. The address in the address bar is correct and if I simply click in the bar and hit enter, it loads the desired customer page. When I manually load the edit page, the edits have saved. What might I be missing here to get the page to re-load after updates on it’s own?

Here is the code:

<?php
require_once '../../../db_php/dbconnectiontickets.php';


$CustomerID=(isset($_GET['updateid'])  ? $_GET['updateid'] : '');
//require_once '../fireytech-project/db_php/dbconnectiontickets.php';
    session_start();

    if(!isset($_SESSION['user'])){
        header('location:../login.php');
    }




$sql = "SELECT * From Customers

           WHERE CustomerID ='$CustomerID'
"
;


$result = $conn->query($sql);
//echo "<pre>";print_r($result);die;
if ($result->num_rows > 0) {

    $row = $result->fetch_all(MYSQLI_ASSOC);
}


/*Update ccustomers table*/
$userName=explode('@',$_SESSION['user']['firstname']);
$userName=$userName[0];


if(!empty($_POST)){
   

    //DateEdited
    $Notes=$conn->real_escape_string($row[0]['Notes']);
    $NotesBilling=$conn->real_escape_string($row[0]['NotesBilling']);
    $company=$conn->real_escape_string($row[0]['Company']);
//    $billedAs=$row[0]['BilledAs'];
    $customerSource=$row[0]['CustomerSource'];
//    $customerType=$row[0]['CustomerType'];
    $customerStatus=$row[0]['CustomerStatus'];
    $donotcontact=$row[0]['donotcontact'];
    $dcpgreeting=$row[0]['dcpgreeting'];
    $dcpemailgroup=$row[0]['dcpemailgroup'];
    $shareddrive=$row[0]['shareddrive'];

    if($_POST['Notes'] !=''){
        $Notes=date('m/d/Y h:m'). ' '.$userName .'rn'.$conn->real_escape_string($_POST['Notes']).'rn'.$conn->real_escape_string($row[0]['Notes']);
        //$Notes=$conn->real_escape_string($Notes);
    }
    if($_POST['NotesBilling'] !=''){
        $NotesBilling=date('m/d/Y h:m'). ' '.$userName .'rn'.$conn->real_escape_string($_POST['NotesBilling']).'rn'.$conn->real_escape_string($row[0]['NotesBilling']);
        //$NotesBilling=$conn->real_escape_string($);
    }

        $company=$conn->real_escape_string($_POST['Company']);

//    if($_POST['BilledAs'] !=''){
//        $billedAs=$conn->real_escape_string($_POST['BilledAs']);

//    }


    if($_POST['CustomerSource'] !=''){
        $customerSource=$conn->real_escape_string($_POST['CustomerSource']);

    }

//    if($_POST['CustomerType'] !=''){
//        $customerType=$conn->real_escape_string($_POST['CustomerType']);

//    }

    if($_POST['CustomerStatus'] !=''){
        $customerStatus=$conn->real_escape_string($_POST['CustomerStatus']);

    }

    if($_POST['donotcontact'] !=''){
        $donotcontact=$conn->real_escape_string($_POST['donotcontact']);

    }  

    if($_POST['dcpgreeting'] !=''){
        $dcpgreeting=$conn->real_escape_string($_POST['dcpgreeting']);

    } 

    if($_POST['dcpemailgroup'] !=''){
        $dcpemailgroup=$conn->real_escape_string($_POST['dcpemailgroup']);

    } 

    if($_POST['shareddrive'] !=''){
        $shareddrive=$conn->real_escape_string($_POST['shareddrive']);

    }               

   // echo "<pre>";print_r($Notes);die;
    $currentDate=date('Y-m-d');

    //$updateSql="UPDATE Customers SET Notes=mysqli_real_escape_string($Notes),NotesBilling=mysqli_real_escape_string($NotesBilling) WHERE CustomerID ='$CustomerID' ";
    $updateSql="UPDATE Customers SET Notes='$Notes',NotesBilling='$NotesBilling',Company='$company',CustomerSource='$customerSource',CustomerStatus='$customerStatus',DateEdited='$currentDate',donotcontact='$donotcontact',dcpgreeting='$dcpgreeting',dcpemailgroup='$dcpemailgroup',shareddrive='$shareddrive' 
                 WHERE CustomerID ='$CustomerID' ";
    $conn->query($updateSql);      

     echo "<meta http-equiv='refresh' content='0'>";
    if ($conn->error) {
        printf("Error message: %sn", $conn->error);die;
    }
    }
  

//echo "<pre>";var_dump($saved);die;
?>