Skrill Gateway failing

Hi David,
I’m posting here the reply I already sent you, for other users’ reference.

The issue is not caused by our plugin. The error message simply says that the data sent to Skrill belongs to an order that was already paid. The order information is generated entirely by WooCommerce, and the Skrill plugin just prepares it and sends it to the Skrill server. If the wrong data is sent, then it means that the wrong data was passed to the Skrill plugin in the first place, by WooCommerce. This could be due by sessions or carts being lost, or mixed up.
I would suggest your developer to focus on WooCommerce sessions, as they are the key of the whole ordering process. The Skrill plugin is merely reporting a “symptom” of an underlying issue, and you can assume that, once the correct data is passed to it, it will work properly.

Thank you Diego.

The problem started to occur when one single website was splited into a multisite 7 websites. Order numbers should be unique but happens to be they are not and the Gateway collapses when finds past Order Numbers which cannot be re-used.

It has been solved with some code on the Plugin to rename Order NUmbers so they are totally unique.

Thank you Diego for your great support