No email is being sent after purchase

[houmanka]

Hi guys,
When user purchases something the email is not going out to the user or admin.

I have changed: Default Order Status to send an invoice to confirmed. All the emails are set up correctly and I get email upon user registration.

So can someone please help me. I am running VM 2

I searched this problem and I got this solution:

I add this to my payment method:
   $modelOrder = VmModel::getModel ('orders');
   $order = array();
   $order['order_status'] = 'C';
   $modelOrder->updateStatusForOneOrder ($virtuemart_order_id, $order, TRUE);

However I get

Fatal error: Call to undefined method MYPDF::SetDefaultMonospacedFont() in {root}/components/com_virtuemart/controllers/invoice.php on line 155