Hello Gwyndaf,
Thank you for using our plugin for VirtueMart.
We are aware of compatibility issue with some third-party OPC.
It would be great if my Stripe plugin could work with many other extensions like One Page Checkout, and "should" in an ideal world. However, I have worked and customised the code a lot already with some of these extensions, that are heavily using Ajax. But I cannot guarantee a full compatibility, with the complexity and diversity of the extensions out there. I do not state otherwise on my website, so one cannot be mislead by a vague promise or suggestion.
Also, in an ideal world, these OPC, changing a critical part of VirtueMart, should work properly with the major payment and shipment methods, and not the other way around. That being said, let's start with getting the Stripe plugin working with your website.
1. Please disable the third-party OPC, and try again, with the default VirtueMart one page checkout. We will be sure that the plugin and settings are good.
2. I am finishing a major upgrade of my Stripe plugin, and the tests with 3rd party OPC are not due yet. What time frame do you have before going into Live Production with the plugin? I can help you on that, and extend the subscription until we have a solution in place for you.
3. I know some work arounds, depending on your needs/settings in OPC, or a temporary solution with payment outside of the merchant website, like the Paypal standard web page.
4. I am not in recent touch with the crowd at CmSmart.net. Please could you check with them if your OPC is up-to-date, and what they say about this issue?
I am looking forward to helping you further!
Kind regards,
Hervé