WHMCS Tags troubleshooting-article Troubleshoot and resolve TypeError guessFileExtension() errors. Troubleshoot and resolve issues accessing the Sign-In Integrations page to configure authentication using Facebook®, Google®, or Twitter™ Sign-In Integrations. Troubleshoot and resolve Unable to communicate with the WHMCS installation errors. Troubleshoot and resolve Unable to connect to the database errors. Troubleshoot and resolve an Unable to display TLD cost pricing error. Troubleshoot and resolve Call to undefined function curl_init() errors. Troubleshoot and resolve Call to undefined method getRawHeader() errors. Troubleshoot and resolve Call to undefined function PHPMailer
HPMailerscapeshellarg() errors. Troubleshoot and resolve issues with broken domain renewal links in emails. Troubleshoot and resolve unexpected client details on an invoice. Troubleshoot and resolve unexpected changes to a service's Next Due Date value. Troubleshoot and resolve issues with customers receiving unexpected subscription cancellation emails from PayPal®. The system is unexpectedly suspending services (for example, hosting accounts). The system is unexpectedly terminating services (for example, hosting accounts). Troubleshoot and resolve unexplained declined cards and failures. Troubleshoot and resolve transactions that the system isn't recording. Troubleshoot and resolve The sender's email address is not registered. errors. Troubleshoot and resolve issues with sending general emails to clients. Troubleshoot and resolve issues with ticket notification emails. Troubleshoot and resolve issues with welcome emails not sending.