Magento - order details are not displayed in the admin panel

Question

We have an ecommerce magento store. Right now, we are experiencing a weird problem, which i am unable to understand and debug.

For some of the orders, no details ar

Answer 1

If the SUPEE-7405 patch has caused this, please check that your system does not run on PHP 5.3.

The patch breaks PHP 5.3 compatibility, by introducing usage of array literals in app/code/core/Mage/Adminhtml/Helper/Sales.php (line 124), which became available in PHP since version 5.4, so the minimum PHP version required, after applying it, is PHP 5.4:

// patched app/code/core/Mage/Adminhtml/Helper/Sales.php lines 121-124
public function escapeHtmlWithLinks($data, $allowedTags = null)
{
    if (!empty($data) && is_array($allowedTags) && in_array('a', $allowedTags)) {
        $links = [];

To fix this, and restore PHP 5.3 compatibility (allowing orders to show up again in admin screens), simply correct this with old PHP5.3 equivalent:

// patched and fixed app/code/core/Mage/Adminhtml/Helper/Sales.php lines 121-124
public function escapeHtmlWithLinks($data, $allowedTags = null)
{
    if (!empty($data) && is_array($allowedTags) && in_array('a', $allowedTags)) {
        $links = array();