Magento 2 Checkout Error – Sorry, No Quotes Are Available for This Order

I never used this carrier, but the messages is added here:

/app/code/core/Mage/XmlConnect/Block/Cart/Paypal/Mecl/Shippingmethods.php:71

So the question is, why is $groups == false?

$groups = $this->getShippingRateGroups();
if ($groups) {
    // ...
} else {
    $message = $this->_quote->isVirtual() ? $this->__('No shipping method required.')
        : $this->__('Sorry, no quotes are available for this order at this time.');
        $methodListXmlObj->addCustomChild('method', null, array('label' => $message));
}

There is only one place I can find where the ShippingRateGroups is set:

/app/code/core/Mage/Paypal/Block/Express/Review.php:216

I searched for setShippingRateGroups() and Shipping_Rate_Groups

This value is somewhere loaded and set implicit. Good luck with the debugging.

The reason was in proccessAdditionalValidation function in Mage_Shipping_Model_Carrier_Abstract class:

    /**
         * Processing additional validation to check is carrier applicable.
         *
         * @param Mage_Shipping_Model_Rate_Request $request
         * @return Mage_Shipping_Model_Carrier_Abstract|Mage_Shipping_Model_Rate_Result_Error|boolean
         */
        public function proccessAdditionalValidation(Mage_Shipping_Model_Rate_Request $request)
        {
            $maxAllowedWeight = (float) $this->getConfigData('max_package_weight');
            $error = null;
            $showMethod = $this->getConfigData('showmethod');
            foreach ($request->getAllItems() as $item) {
                if ($item->getProduct() && $item->getProduct()->getId()) {

// here I got true

                    if ($item->getProduct()->getWeight() > $maxAllowedWeight) {                         $error = Mage::getModel('shipping/rate_result_error');
                        $error->setCarrier($this->_code)
                            ->setCarrierTitle($this->getConfigData('title'));
                        $errorMsg = $this->getConfigData('specificerrmsg');
                        $error->setErrorMessage($errorMsg?$errorMsg:Mage::helper('shipping')->__('The shipping module is not available.'));
                        break;
                    }
                }
            }
            if (null !== $error && $showMethod) {
                return $error;
            } elseif (null !== $error) {
                return false;
            }
            return $this;
        }