Delete /var/cache/dev/class_index.php (and /var/cache/prod/ in production).
/override/modules/customshipping/classes/CustomShippingCalculator.php Your override must extend the original class and use the same namespace.
OriginalClassNameOverride (e.g., CartControllerOverride , PaymentModuleOverride )
// New logic: add $5 handling fee for fragile items $extraFee = 0; foreach ($products as $product) if ($product['is_fragile']) $extraFee += 5;
PrestaShop does not automatically scan new overrides. You must clear the class index.
In Back Office → Advanced Parameters → Performance → click "Clear cache". Important Naming Convention The override class name must be unique. The standard convention is:
