PHP error with the zone shipping module

[Ajeh]

Do you have any checkout add ons?

Can you post the full contents of your file:
/includes/modules/pages/checkout_shipping/header_php.php

What version of Zen Cart is this again?

[izar74]

Do you have any checkout add ons?

Can you post the full contents of your file:
/includes/modules/pages/checkout_shipping/header_php.php

What version of Zen Cart is this again?

One thing at a time:

Sorry Linda I made a mistake in the previous reply...

The correct answer is:

Shipping From= Italy
Shipping to = US, EU (all the state of UE)
Weight = 1

What I meant is that if the customer has a registered address outside IT (tha is the country code in the "Skip Countries" field) the error doesn't appear.
The log error is written every time else, the only solution is to remove the IT code from the fied.

Question 2:
Yes I have few add on that modify checkout here the list:

- Stock by attributes 1.5.1.2
- Reward Point full 2.1b

The zen cart version is 1.51.
Note: even in a fresh new install i got the same error without any add-ons.

Here the /includes/modules/pages/checkout_shipping/header_php.php

<?php
/**
 * Checkout Shipping Page
 *
 * @package page
 * @copyright Copyright 2003-2011 Zen Cart Development Team
 * @copyright Portions Copyright 2003 osCommerce
 * @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
 * @version $Id: header_php.php 18697 2011-05-04 14:35:20Z wilt $
 * Updated for Stock by Attributes 1.5.1.2 by POTTERYHOUSE
 */
// This should be first line of the script:
  $zco_notifier->notify('NOTIFY_HEADER_START_CHECKOUT_SHIPPING');

  require_once(DIR_WS_CLASSES . 'http_client.php');

// if there is nothing in the customers cart, redirect them to the shopping cart page
  if ($_SESSION['cart']->count_contents() <= 0) {
    zen_redirect(zen_href_link(FILENAME_TIME_OUT));
  }

// if the customer is not logged on, redirect them to the login page
  if (!isset($_SESSION['customer_id']) || !$_SESSION['customer_id']) {
    $_SESSION['navigation']->set_snapshot();
    zen_redirect(zen_href_link(FILENAME_LOGIN, '', 'SSL'));
  } else {
    // validate customer
    if (zen_get_customer_validate_session($_SESSION['customer_id']) == false) {
      $_SESSION['navigation']->set_snapshot(array('mode' => 'SSL', 'page' => FILENAME_CHECKOUT_SHIPPING));
      zen_redirect(zen_href_link(FILENAME_LOGIN, '', 'SSL'));
    }
  }

// Validate Cart for checkout
  $_SESSION['valid_to_checkout'] = true;
  $_SESSION['cart']->get_products(true);
  if ($_SESSION['valid_to_checkout'] == false) {
    $messageStack->add('header', ERROR_CART_UPDATE, 'error');
    zen_redirect(zen_href_link(FILENAME_SHOPPING_CART));
  }

// Stock Check
  if ( (STOCK_CHECK == 'true') && (STOCK_ALLOW_CHECKOUT != 'true') ) {
    $products = $_SESSION['cart']->get_products();
    for ($i=0, $n=sizeof($products); $i<$n; $i++) {

        // START "Stock by Attributes"
        // Added to allow individual stock of different attributes
        unset($attributes);
        if(is_array($products[$i]['attributes'])){
            $attributes = $products[$i]['attributes'];
        } 
        else{
              $attributes = null;
        }
    
        if(!empty($attributes)){
            if (zen_check_stock($products[$i]['id'], $products[$i]['quantity'], $attributes)) {
                zen_redirect(zen_href_link(FILENAME_SHOPPING_CART));
                break;
            }
        }
        else{
      if (zen_check_stock($products[$i]['id'], $products[$i]['quantity'])) {
        zen_redirect(zen_href_link(FILENAME_SHOPPING_CART));
        break;
      }
    }
  }
    // END "Stock by Attributes"
 }

// if no shipping destination address was selected, use the customers own address as default
  if (!$_SESSION['sendto']) {
    $_SESSION['sendto'] = $_SESSION['customer_default_address_id'];
  } else {
// verify the selected shipping address
    $check_address_query = "SELECT count(*) AS total
                            FROM   " . TABLE_ADDRESS_BOOK . "
                            WHERE  customers_id = :customersID
                            AND    address_book_id = :addressBookID";

    $check_address_query = $db->bindVars($check_address_query, ':customersID', $_SESSION['customer_id'], 'integer');
    $check_address_query = $db->bindVars($check_address_query, ':addressBookID', $_SESSION['sendto'], 'integer');
    $check_address = $db->Execute($check_address_query);

    if ($check_address->fields['total'] != '1') {
      $_SESSION['sendto'] = $_SESSION['customer_default_address_id'];
      $_SESSION['shipping'] = '';
    }
  }

  require(DIR_WS_CLASSES . 'order.php');
  $order = new order;

// register a random ID in the session to check throughout the checkout procedure
// against alterations in the shopping cart contents
if (isset($_SESSION['cart']->cartID)) {
  if (!isset($_SESSION['cartID']) || $_SESSION['cart']->cartID != $_SESSION['cartID']) {
    $_SESSION['cartID'] = $_SESSION['cart']->cartID;
  }
} else {
  zen_redirect(zen_href_link(FILENAME_TIME_OUT));
}

// if the order contains only virtual products, forward the customer to the billing page as
// a shipping address is not needed
  if ($order->content_type == 'virtual') {
    $_SESSION['shipping'] = 'free_free';
    $_SESSION['shipping']['title'] = 'free_free';
    $_SESSION['sendto'] = false;
    zen_redirect(zen_href_link(FILENAME_CHECKOUT_PAYMENT, '', 'SSL'));
  }

  $total_weight = $_SESSION['cart']->show_weight();
  $total_count = $_SESSION['cart']->count_contents();

// load all enabled shipping modules
  require(DIR_WS_CLASSES . 'shipping.php');
  $shipping_modules = new shipping;

  $pass = true;
  if ( defined('MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING') && (MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING == 'true') ) {
    $pass = false;

    switch (MODULE_ORDER_TOTAL_SHIPPING_DESTINATION) {
      case 'national':
        if ($order->delivery['country_id'] == STORE_COUNTRY) {
          $pass = true;
        }
        break;
      case 'international':
        if ($order->delivery['country_id'] != STORE_COUNTRY) {
          $pass = true;
        }
        break;
      case 'both':
        $pass = true;
        break;
    }

    $free_shipping = false;
    if ( ($pass == true) && ($_SESSION['cart']->show_total() >= MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING_OVER) ) {
      $free_shipping = true;
    }
  } else {
    $free_shipping = false;
  }

  require(DIR_WS_MODULES . zen_get_module_directory('require_languages.php'));

  if (isset($_SESSION['comments'])) {
    $comments = $_SESSION['comments'];
  }


// process the selected shipping method
  if ( isset($_POST['action']) && ($_POST['action'] == 'process') ) {
    if (zen_not_null($_POST['comments'])) {
      $_SESSION['comments'] = zen_db_prepare_input($_POST['comments']);
    }
    $comments = $_SESSION['comments'];
    $quote = array();

    if ( (zen_count_shipping_modules() > 0) || ($free_shipping == true) ) {
      if ( (isset($_POST['shipping'])) && (strpos($_POST['shipping'], '_')) ) {
        /**
         * check to be sure submitted data hasn't been tampered with
         */
        if ($_POST['shipping'] == 'free_free' && ($order->content_type != 'virtual' && !$pass)) {
          $quote['error'] = 'Invalid input. Please make another selection.';
        } else {
          $_SESSION['shipping'] = $_POST['shipping'];
        }

        list($module, $method) = explode('_', $_SESSION['shipping']);
        if ( is_object($$module) || ($_SESSION['shipping'] == 'free_free') ) {
          if ($_SESSION['shipping'] == 'free_free') {
            $quote[0]['methods'][0]['title'] = FREE_SHIPPING_TITLE;
            $quote[0]['methods'][0]['cost'] = '0';
          } else {
            $quote = $shipping_modules->quote($method, $module);
          }
          if (isset($quote['error'])) {
            $_SESSION['shipping'] = '';
          } else {
            if ( (isset($quote[0]['methods'][0]['title'])) && (isset($quote[0]['methods'][0]['cost'])) ) {
              $_SESSION['shipping'] = array('id' => $_SESSION['shipping'],
                                'title' => (($free_shipping == true) ?  $quote[0]['methods'][0]['title'] : $quote[0]['module'] . ' (' . $quote[0]['methods'][0]['title'] . ')'),
                                'cost' => $quote[0]['methods'][0]['cost']);

              zen_redirect(zen_href_link(FILENAME_CHECKOUT_PAYMENT, '', 'SSL'));
            }
          }
        } else {
          $_SESSION['shipping'] = false;
        }
      }
    } else {
      $_SESSION['shipping'] = false;

      zen_redirect(zen_href_link(FILENAME_CHECKOUT_PAYMENT, '', 'SSL'));
    }
  }

// get all available shipping quotes
  $quotes = $shipping_modules->quote();

  // check that the currently selected shipping method is still valid (in case a zone restriction has disabled it, etc)
  if (isset($_SESSION['shipping']) && $_SESSION['shipping'] != FALSE && $_SESSION['shipping'] != '') {
    $checklist = array();
    foreach ($quotes as $key=>$val) {
      foreach($val['methods'] as $key2=>$method) {
        $checklist[] = $val['id'] . '_' . $method['id'];
      }
    }
    $checkval = (is_array($_SESSION['shipping']) ? $_SESSION['shipping']['id'] : $_SESSION['shipping']);
    if (!in_array($checkval, $checklist)) {
      $messageStack->add('checkout_shipping', ERROR_PLEASE_RESELECT_SHIPPING_METHOD, 'error');
    }
  }

// if no shipping method has been selected, automatically select the cheapest method.
// if the modules status was changed when none were available, to save on implementing
// a javascript force-selection method, also automatically select the cheapest shipping
// method if more than one module is now enabled
  if ( !$_SESSION['shipping'] || ( $_SESSION['shipping'] && ($_SESSION['shipping'] == false) && (zen_count_shipping_modules() > 1) ) ) $_SESSION['shipping'] = $shipping_modules->cheapest();


  // Should address-edit button be offered?
  $displayAddressEdit = (MAX_ADDRESS_BOOK_ENTRIES >= 2);

  // if shipping-edit button should be overridden, do so
  $editShippingButtonLink = zen_href_link(FILENAME_CHECKOUT_SHIPPING_ADDRESS, '', 'SSL');
  if (isset($_SESSION['payment']) && method_exists($$_SESSION['payment'], 'alterShippingEditButton')) {
    $theLink = $$_SESSION['payment']->alterShippingEditButton();
    if ($theLink) {
      $editShippingButtonLink = $theLink;
      $displayAddressEdit = true;
    }
  }

  $breadcrumb->add(NAVBAR_TITLE_1, zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL'));
  $breadcrumb->add(NAVBAR_TITLE_2);

// This should be last line of the script:
  $zco_notifier->notify('NOTIFY_HEADER_END_CHECKOUT_SHIPPING');

[izar74]

Yes, and if I had/remembered the answer, I would have shared it..

Ummm.. well from where I was sitting Linda was/is helping you.. my point was that snarky sounding comments are generally not helpful around here when someone is helping.. Especially someone as nice as Linda.. IJS..

You couldn't be more right and that go in both direction.
I probably get a little upsetted by a word that really meaned no harm but You know sometime when everything goes wrong just a little spark can rise a fire.

[DivaVocals]

You couldn't be more right and that go in both direction.
I probably get a little upsetted by a word that really meaned no harm but You know sometime when everything goes wrong just a little spark can rise a fire.

I do understand.. but as a piece of friendly advice.. temper tantrums directed to the community are generally not well received.. That said solo temper tantrums are not an issue.. I've had PLENTY of those..

[Ajeh]

Go to your Zen Cart Admin and go to Locations / Taxes ... Countries ...

Find Italy ...

Click on it and look in the URL, what is the cID for that?

What are the other settings for the whole row?

Next, go to the Customers in the Admin, and EDIT the customer that you are using for this checkout ...

Is the Country setup right for Italy?

I am assuming that this is your test Customer account that you are testing things with and that you can login as that customer ...

Login as that Customer and go to the My Account and check the Addresses setup for it ...

Edit the one(s) for Italy and do an Update ...

So far, nothing I have done in testing here as triggered this error that you are getting ...

You have Zone Rates setup to Weight and have the Skip Countries set to:
IT

You have only the first Zone 1 defined as:
US, CA

and are not using any other Zones ...

The only other shipping module installed is Flat Rate flat and the Zone Rate zones is green dot and Flat Rate flat is green dot and ALL other shipping modules are red dots ... correct?

[izar74]

Go to your Zen Cart Admin and go to Locations / Taxes ... Countries ...

Find Italy ...

Click on it and look in the URL, what is the cID for that?

What are the other settings for the whole row?

url and cID = /countries.php?page=6&cID=105
Setting = ISO Code (2): IT ISO Code (3): ITA Address Format: 5

Next, go to the Customers in the Admin, and EDIT the customer that you are using for this checkout ...

Is the Country setup right for Italy?

I am assuming that this is your test Customer account that you are testing things with and that you can login as that customer ...

Login as that Customer and go to the My Account and check the Addresses setup for it ...

Edit the one(s) for Italy and do an Update ...

Yes is the account i use for testing, and i can login as customer.
Did as You say, edited the adresses and saved it (was already set with Italy as country)

Yet the error is generated.

So far, nothing I have done in testing here as triggered this error that you are getting ...

May I ask what version of PHP and MYSQL are You testing on?

You have Zone Rates setup to Weight and have the Skip Countries set to:
IT

You have only the first Zone 1 defined as:
US, CA

and are not using any other Zones ...

The only other shipping module installed is Flat Rate flat and the Zone Rate zones is green dot and Flat Rate flat is green dot and ALL other shipping modules are red dots ... correct?

All damned correct...
I've tryed this thing on a fresh new install, no mods or anything and the error is generated in the same way, the only thing i'm gonna try is using the very base Zencart 1.51 not the Italian version (localization made by www.zencartitalia.it).

[izar74]

Update: I've made a fresh new install with the english version 1.51, no add-on, installed with demo data. Removed all the shiping except Flat rate and Zone rates.
The error is still there, same as before:

Invalid argument supplied for foreach() in C:\wamp\www\negozio151eng\includes\modules\pages\checkout_shipping\header_php.php on line 191 

<?php
/**
 * Checkout Shipping Page
 *
 * @package page
 * @copyright Copyright 2003-2011 Zen Cart Development Team
 * @copyright Portions Copyright 2003 osCommerce
 * @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
 * @version $Id: header_php.php 18697 2011-05-04 14:35:20Z wilt $
 */
// This should be first line of the script:
  $zco_notifier->notify('NOTIFY_HEADER_START_CHECKOUT_SHIPPING');

  require_once(DIR_WS_CLASSES . 'http_client.php');

// if there is nothing in the customers cart, redirect them to the shopping cart page
  if ($_SESSION['cart']->count_contents() <= 0) {
    zen_redirect(zen_href_link(FILENAME_TIME_OUT));
  }

// if the customer is not logged on, redirect them to the login page
  if (!isset($_SESSION['customer_id']) || !$_SESSION['customer_id']) {
    $_SESSION['navigation']->set_snapshot();
    zen_redirect(zen_href_link(FILENAME_LOGIN, '', 'SSL'));
  } else {
    // validate customer
    if (zen_get_customer_validate_session($_SESSION['customer_id']) == false) {
      $_SESSION['navigation']->set_snapshot(array('mode' => 'SSL', 'page' => FILENAME_CHECKOUT_SHIPPING));
      zen_redirect(zen_href_link(FILENAME_LOGIN, '', 'SSL'));
    }
  }

// Validate Cart for checkout
  $_SESSION['valid_to_checkout'] = true;
  $_SESSION['cart']->get_products(true);
  if ($_SESSION['valid_to_checkout'] == false) {
    $messageStack->add('header', ERROR_CART_UPDATE, 'error');
    zen_redirect(zen_href_link(FILENAME_SHOPPING_CART));
  }

// Stock Check
  if ( (STOCK_CHECK == 'true') && (STOCK_ALLOW_CHECKOUT != 'true') ) {
    $products = $_SESSION['cart']->get_products();
    for ($i=0, $n=sizeof($products); $i<$n; $i++) {
      if (zen_check_stock($products[$i]['id'], $products[$i]['quantity'])) {
        zen_redirect(zen_href_link(FILENAME_SHOPPING_CART));
        break;
      }
    }
  }
// if no shipping destination address was selected, use the customers own address as default
  if (!$_SESSION['sendto']) {
    $_SESSION['sendto'] = $_SESSION['customer_default_address_id'];
  } else {
// verify the selected shipping address
    $check_address_query = "SELECT count(*) AS total
                            FROM   " . TABLE_ADDRESS_BOOK . "
                            WHERE  customers_id = :customersID
                            AND    address_book_id = :addressBookID";

    $check_address_query = $db->bindVars($check_address_query, ':customersID', $_SESSION['customer_id'], 'integer');
    $check_address_query = $db->bindVars($check_address_query, ':addressBookID', $_SESSION['sendto'], 'integer');
    $check_address = $db->Execute($check_address_query);

    if ($check_address->fields['total'] != '1') {
      $_SESSION['sendto'] = $_SESSION['customer_default_address_id'];
      $_SESSION['shipping'] = '';
    }
  }

  require(DIR_WS_CLASSES . 'order.php');
  $order = new order;

// register a random ID in the session to check throughout the checkout procedure
// against alterations in the shopping cart contents
if (isset($_SESSION['cart']->cartID)) {
  if (!isset($_SESSION['cartID']) || $_SESSION['cart']->cartID != $_SESSION['cartID']) {
    $_SESSION['cartID'] = $_SESSION['cart']->cartID;
  }
} else {
  zen_redirect(zen_href_link(FILENAME_TIME_OUT));
}

// if the order contains only virtual products, forward the customer to the billing page as
// a shipping address is not needed
  if ($order->content_type == 'virtual') {
    $_SESSION['shipping'] = 'free_free';
    $_SESSION['shipping']['title'] = 'free_free';
    $_SESSION['sendto'] = false;
    zen_redirect(zen_href_link(FILENAME_CHECKOUT_PAYMENT, '', 'SSL'));
  }

  $total_weight = $_SESSION['cart']->show_weight();
  $total_count = $_SESSION['cart']->count_contents();

// load all enabled shipping modules
  require(DIR_WS_CLASSES . 'shipping.php');
  $shipping_modules = new shipping;

  $pass = true;
  if ( defined('MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING') && (MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING == 'true') ) {
    $pass = false;

    switch (MODULE_ORDER_TOTAL_SHIPPING_DESTINATION) {
      case 'national':
        if ($order->delivery['country_id'] == STORE_COUNTRY) {
          $pass = true;
        }
        break;
      case 'international':
        if ($order->delivery['country_id'] != STORE_COUNTRY) {
          $pass = true;
        }
        break;
      case 'both':
        $pass = true;
        break;
    }

    $free_shipping = false;
    if ( ($pass == true) && ($_SESSION['cart']->show_total() >= MODULE_ORDER_TOTAL_SHIPPING_FREE_SHIPPING_OVER) ) {
      $free_shipping = true;
    }
  } else {
    $free_shipping = false;
  }

  require(DIR_WS_MODULES . zen_get_module_directory('require_languages.php'));

  if (isset($_SESSION['comments'])) {
    $comments = $_SESSION['comments'];
  }


// process the selected shipping method
  if ( isset($_POST['action']) && ($_POST['action'] == 'process') ) {
    if (zen_not_null($_POST['comments'])) {
      $_SESSION['comments'] = zen_db_prepare_input($_POST['comments']);
    }
    $comments = $_SESSION['comments'];
    $quote = array();

    if ( (zen_count_shipping_modules() > 0) || ($free_shipping == true) ) {
      if ( (isset($_POST['shipping'])) && (strpos($_POST['shipping'], '_')) ) {
        /**
         * check to be sure submitted data hasn't been tampered with
         */
        if ($_POST['shipping'] == 'free_free' && ($order->content_type != 'virtual' && !$pass)) {
          $quote['error'] = 'Invalid input. Please make another selection.';
        } else {
          $_SESSION['shipping'] = $_POST['shipping'];
        }

        list($module, $method) = explode('_', $_SESSION['shipping']);
        if ( is_object($$module) || ($_SESSION['shipping'] == 'free_free') ) {
          if ($_SESSION['shipping'] == 'free_free') {
            $quote[0]['methods'][0]['title'] = FREE_SHIPPING_TITLE;
            $quote[0]['methods'][0]['cost'] = '0';
          } else {
            $quote = $shipping_modules->quote($method, $module);
          }
          if (isset($quote['error'])) {
            $_SESSION['shipping'] = '';
          } else {
            if ( (isset($quote[0]['methods'][0]['title'])) && (isset($quote[0]['methods'][0]['cost'])) ) {
              $_SESSION['shipping'] = array('id' => $_SESSION['shipping'],
                                'title' => (($free_shipping == true) ?  $quote[0]['methods'][0]['title'] : $quote[0]['module'] . ' (' . $quote[0]['methods'][0]['title'] . ')'),
                                'cost' => $quote[0]['methods'][0]['cost']);

              zen_redirect(zen_href_link(FILENAME_CHECKOUT_PAYMENT, '', 'SSL'));
            }
          }
        } else {
          $_SESSION['shipping'] = false;
        }
      }
    } else {
      $_SESSION['shipping'] = false;

      zen_redirect(zen_href_link(FILENAME_CHECKOUT_PAYMENT, '', 'SSL'));
    }
  }

// get all available shipping quotes
  $quotes = $shipping_modules->quote();

  // check that the currently selected shipping method is still valid (in case a zone restriction has disabled it, etc)
  if (isset($_SESSION['shipping']) && $_SESSION['shipping'] != FALSE && $_SESSION['shipping'] != '') {
    $checklist = array();
    foreach ($quotes as $key=>$val) {
      foreach($val['methods'] as $key2=>$method) {
        $checklist[] = $val['id'] . '_' . $method['id'];
      }
    }
    $checkval = (is_array($_SESSION['shipping']) ? $_SESSION['shipping']['id'] : $_SESSION['shipping']);
    if (!in_array($checkval, $checklist)) {
      $messageStack->add('checkout_shipping', ERROR_PLEASE_RESELECT_SHIPPING_METHOD, 'error');
    }
  }

// if no shipping method has been selected, automatically select the cheapest method.
// if the modules status was changed when none were available, to save on implementing
// a javascript force-selection method, also automatically select the cheapest shipping
// method if more than one module is now enabled
  if ( !$_SESSION['shipping'] || ( $_SESSION['shipping'] && ($_SESSION['shipping'] == false) && (zen_count_shipping_modules() > 1) ) ) $_SESSION['shipping'] = $shipping_modules->cheapest();


  // Should address-edit button be offered?
  $displayAddressEdit = (MAX_ADDRESS_BOOK_ENTRIES >= 2);

  // if shipping-edit button should be overridden, do so
  $editShippingButtonLink = zen_href_link(FILENAME_CHECKOUT_SHIPPING_ADDRESS, '', 'SSL');
  if (isset($_SESSION['payment']) && method_exists($$_SESSION['payment'], 'alterShippingEditButton')) {
    $theLink = $$_SESSION['payment']->alterShippingEditButton();
    if ($theLink) {
      $editShippingButtonLink = $theLink;
      $displayAddressEdit = true;
    }
  }

  $breadcrumb->add(NAVBAR_TITLE_1, zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL'));
  $breadcrumb->add(NAVBAR_TITLE_2);

// This should be last line of the script:
  $zco_notifier->notify('NOTIFY_HEADER_END_CHECKOUT_SHIPPING');

[izar74]

I've put everything on a test server:

http://www.viaincenso.com/

http://www.viaincenso.com/admintest for admin.

Sent Linda the login info and ftp info if you want to have a look

[izar74]

Update: the error still generate but if you go for checkout, and go streight to the end no error is generate (seem so at the moment, still investigating) but if for any reason you decide to change something and go back or restar the checkout process the error pop!

[Ajeh]

I am assuming that while the error is generated in your debug logs ... that the checkout is still working ...

I have generated the error, finally, and come up with a fix for you ...

Edit the file:
/includes/modules/shipping/checkout_shipping/header_php.php

and add the code in RED:

  // check that the currently selected shipping method is still valid (in case a zone restriction has disabled it, etc)
  if (isset($_SESSION['shipping']) && $_SESSION['shipping'] != FALSE && $_SESSION['shipping'] != '') {
    $checklist = array();
    foreach ($quotes as $key=>$val) {
      if ($val['methods'] != '') {
        foreach($val['methods'] as $key2=>$method) {
          $checklist[] = $val['id'] . '_' . $method['id'];
        }
      } else {
        // skip
      }
    }
    $checkval = (is_array($_SESSION['shipping']) ? $_SESSION['shipping']['id'] : $_SESSION['shipping']);
    if (!in_array($checkval, $checklist)) {
      $messageStack->add('checkout_shipping', ERROR_PLEASE_RESELECT_SHIPPING_METHOD, 'error');
    }
  }

// if no shipping method has been selected, automatically select the cheapest method.

See if this stops you from generating any more debug logs ...