WHMCS Tags configuration-php Troubleshoot and resolve InvalidArgumentException: Query string must not include a URI fragment errors. Customize your own minimum and maximum length limits for domain names if you don't want to use the default for the domain extension (TLD). You can configure WHMCS to use an encrypted MySQL® database. When you move your WHMCS installation from one server to another, you may need to perform additional steps like updating your license. When you move your WHMCS installation from one subdomain to another on the same server, you may need to perform additional steps like updating your license. You can take steps to optimize performance on larger installations.