Magento Fatal error: Class 'Mage_Order_Helper_Data' not found <p>I must be over-thinking this issue, but I can't seem to resolve it. I need to overwrite the <strong>sendNewOrderEmail</strong> function of <strong>Mage_Sales_Model_Order</strong>. When I do this I lose my transactional email templates in the drop-down in the admin interface.</p> <p>Error:</p> <pre><code>Fatal error: Class 'Mage_Order_Helper_Data' not found </code></pre> <p>/app/code/local/Mine/Sales/etc/config.xml</p> <pre><code>&lt;?xml version="1.0"?&gt; &lt;config&gt; &lt;global&gt; &lt;models&gt; &lt;sales&gt; &lt;rewrite&gt; &lt;order&gt;Mine_Sales_Model_Order&lt;/order&gt; &lt;/rewrite&gt; &lt;/sales&gt; &lt;/models&gt; &lt;helpers&gt; &lt;sales&gt; &lt;class&gt;Mine_Sales_Helper&lt;/class&gt; &lt;/sales&gt; &lt;/helpers&gt; &lt;template&gt; &lt;email&gt; &lt;umicrosite_order_alert module="order"&gt; &lt;label&gt;Vendor Order Alert&lt;/label&gt; &lt;file&gt;umicrosite_order_alert.html&lt;/file&gt; &lt;type&gt;html&lt;/type&gt; &lt;/umicrosite_order_alert&gt; &lt;/email&gt; &lt;/template&gt; &lt;/global&gt; &lt;/config&gt; </code></pre> <p>/app/code/local/Mine/Model/Sales/Order.php</p> <pre><code>&lt;?php class Mine_Sales_Model_Order extends Mage_Sales_Model_Order { /** * Send email with order data * * @return Mage_Sales_Model_Order */ public function sendNewOrderEmail() { $storeId = $this-&gt;getStore()-&gt;getId(); $emailTemplate = Mage::getModel('core/email_template')-&gt;loadDefault('umicrosite_order_alert'); $emailTemplate-&gt;setSender(Mage::getStoreConfig(self::XML_PATH_EMAIL_IDENTITY, $storeId)); $emailTemplate-&gt;setSenderEmail(Mage::getStoreConfig('trans_email/ident_sales/email')); $emailTemplate-&gt;setSenderName(Mage::getStoreConfig('trans_email/ident_sales/name')); $emailTemplate-&gt;setType('html'); $emailTemplate-&gt;setTemplateSubject('New Order from my store'); $emails = array(); foreach ($this-&gt;getItemsCollection() as $item) { $vendor = Mage::helper('udropship')-&gt;getVendor($item-&gt;getProduct()); $email = $vendor-&gt;getEmail(); if (!in_array($email,$emails)) { $emails[] = $email; $emailTemplateVariables = array(); $emailTemplateVariables = array('vendor_name'=&gt;$vendor-&gt;getVendorName()); $emailTemplate-&gt;send($email, $vendor-&gt;getVendorName(), $emailTemplateVariables); } } parent::sendNewOrderEmail(); } } </code></pre> <p>/app/code/local/Mine/Sales/Helper/Data.php</p> <pre><code>&lt;?php class Mine_Sales_Helper_Data extends Mage_Sales_Helper_Data { } </code></pre> <p>If I change my Data.php to:</p> <pre><code>class Mage_Order_Helper_Data extends Mage_Core_Helper_Abstract </code></pre> <p>It causes Class 'Mine_Sales_Helper_Data' not found.</p> <p>What am I doing wrong???</p>