I'm in the process of moving my shopping cart from ePages to Zen Cart. I first installed the Worldpay module in Zen Cart at the beginning of September, and have been successfully running it in test mode. I tested it last night and this morning and Worldpay payments are no longer working. It is failing at the callback stage. The last time I tested it was on Tuesday morning and everything was fine. When I test it now it fails and I don't even receive failed connection emails from Worldpay, which is worrying. I am using the following for my callback URL: https://<wpdisplay item="MC_callback">

I have tested connections from outside to my server on port 443 (https) and that is OK. I have not made any changes since Tuesday.

Are any other Zen Cart Worldpay module users having problems, or is it just me?