Since some point around 20/12 onwards our shipping platform, Zen Stores, has been unable to pull orders from Woocommerce via the REST API. Apparently the API should be returning a JSON file but is currently returning HTML. I have what is being returned by the API Query and it looks to be an unhandled PHP error. Needs investigating and solving to the point where orders are coming back into Zen Stores via the automated sync process in Zen. Zen have checked and are adamant the issue is with our site.