WHMCS Tags configuration-php WHMCS includes features to help keep your data safe, and we recommend taking additional steps to secure your WHMCS installation further. The first step to using WHMCS is installing it on your server. WHMCS includes an easy browser installation tool to suit most users' needs. If you want more configuration options than browser-based installation offers, you can install and upgrade WHMCS on the command line. For successful installation, updates, and operation, your system must meet the minimum system requirements for your WHMCS version. The configuration.php file contains many of the most important and sensitive configuration details for your WHMCS installation. When you secure your installation, we recommend adjusting the permissions for the configuration.php file to protect your sensitive data. Troubleshoot and resolve You are attempting to access the admin area via a directory that is not configured. errors. Troubleshoot and resolve Application configuration file is not writable errors. 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. This requires additional steps to add settings to your configuration.php file. 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. As your database size increases, you may experience slower page loads and other speed-related issues. Optimizing your database and reducing unnecessary data can help WHMCS run faster.