In this page we will go through troubleshooting most common issues regarding WHMCS payment gateway module. Our WHMCS payment gateway module is fully tested and it should be automatically processing all paid invoices by default once you set it up. However due to other badly coded modules installed on your website or other wrong settings you may face some problems. Here on this page we will guide you on how to fix most of these problems. If you can’t do it yourself our support team can help you for free. proble problems. If you can’t do it yourself our support team can help you for free.ms. If you can’t do it yourself our support team can help you for free.