Magento registration returns 'Last name cannot be empty'

Question

I am trying to deploy Magento 1.9.2.1. I used the package from the official site.

But a strange thing happened to me. Among all the instances I deploy, it fails at any page that requires validation of a customer information (registration, etc.). It returns the error 'Last name cannot be empty'. But even stranger, there were 1 or 2 times of success before the errors. That is, the error only happens after I have created 1 or 2 accounts.

I found that the validation method is in the model, as:

if (!Zend_Validate::is( trim($this->getLastname()) , 'NotEmpty')) {
            $errors[] = Mage::helper('customer')->__('The last name cannot be empty.');
}

So I added some lines before it.

$errors[] = Mage::helper('customer')->__('The first name cannot be empty.');
$errors[] = Mage::helper('customer')->__($this->getFirstName());
$errors[] = Mage::helper('customer')->__($this->getLastName());
$errors[] = Mage::helper('customer')->__($this->getEmail());

This time there are 5 errors displayed at the registration page. As expected, the first is 'The first name cannot be empty.'. But the second and third are all empty. The fourth is the email address I typed in.

Here comes another problem. The validation of the first name comes before that of the last name. Were they all empty, how could the error message be only 'The last name cannot be empty.'?

And more substantially, why can I register at the very beginning? What is the substantial problem?

UPDATE: If I comment the validation for the two names, there are no more errors. But the account created has its last name empty, while first name as I typed in.

UPDATE 2:

print_r($this->getRequest()->getPost('lastname'));
print_r($this->getRequest()->getPost('firstname'));

These lines gives the posted data as expected.

Answer 1

Check if lastname attribute is present in your customer_form_attribute table for checkout_register form and other forms.

To list available fields on checkout_register form, use:

SELECT `main_table`.*, ea.attribute_code
FROM `customer_form_attribute` AS `main_table`
inner join eav_attribute ea on main_table.attribute_id = ea.attribute_id
WHERE (`main_table`.`form_code` = 'checkout_register')

Note the solution above is for registering customer on checkout form only. To get a list of available forms do SELECT * FROM customer_form_attribute.

Possible causes

In my case the problem happened after editing the attribute in admin, using a module that ignored the existence of checkout_register form (Clarion_Customerattribute).