oops-errors

General errors can occur in many places throughout WHMCS, and can be due to many different problems. However, fixing them is often simple.

Each addon module has specific errors that you might encounter.

Authentication issues may include inability to log in, unexpected logouts, or errors while using other authentication methods.

When you install WHMCS on a server, make sure to watch for errors both during and after the installation process.

Issues with invoices and invoice generation can be due to many causes, some of which may not be obvious at first.

Make sure to troubleshoot and resolve any issues with payment gateways, payments, currencies, or related features as soon as possible.

Troubleshoot and resolve Oops! InvalidDomain: The domain is invalid errors while managing domains in the Admin Area.

Troubleshoot and resolve 1062 Duplicate entry for key tblconfiguration.PRIMARY errors.

Troubleshoot and resolve 1062 Duplicate entry for key tblinvoices.PRIMARY errors.

Error pages display friendly, styled messages about error conditions. All of WHMCS's error pages are fully customizable for your needs.

Troubleshoot and resolve main(): Failed opening required '/path/to/whmcs/..filename.php' errors.

Troubleshoot and resolve Oops! Access Denied - Forbidden errors while logging in to WHMCS.

Troubleshoot and resolve Oops! errors.

Troubleshoot and resolve an Oops Error: Module Not Found error.

Troubleshoot and resolve Call to undefined function PHPMailer HPMailerscapeshellarg() errors.