Suddenly order not displaying in customer account or admin

• Zen Cart version
• Not upgraded - fresh install 2-3 weeks ago
• no addons - using Apparel boutique template
• looked in FAQ area - tried fixes - including checking debug logs, etc

I had a problem tonight when a customer placed an order - I only use Paypal. The order went through - I received the payment via Paypal, however, no order was created in their account and as such, no download links were generated. I checked the log files and no order is in there either.

I checked phpmyadmin - and no order shows up there either. Somehow the customer managed to create an account and pay without creating a record.

I've had several successful payments/downloads - until tonight.

I'd been running the store - same host, different domain name, for a year previously with no problems.

Any suggestions on where to look to find out what went wrong?

Thank you

The symptoms you describe are classic symptoms of using "PayPal Website Payments Standard" and not Express Checkout.
The problem is a result of a communications break between PayPal's server and your server, or a problem with your server processing the background notification received from PayPal. These problems don't occur when you use Express Checkout. Best fix: click "Remove" on Website Payments Standard, and click "Install" on Express Checkout, and configure it: https://www.zen-cart.com/getpaypal

Also, you didn't state which version of Zen Cart you're using. If you're using an older version without security patches installed, you might be vulnerable to being hacked, in which case that could be another cause of your symptoms.