https://docs.whmcs.com/9-1/tags/system-requirements/Recent content in system-requirements onHugo -- gohugo.iohttps://docs.whmcs.com/9-1/troubleshooting/general-troubleshooting/general-troubleshooting/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/troubleshooting/general-troubleshooting/general-troubleshooting/Landing page linking to troubleshooting articles for general errors, display issues, file and ionCube encoding errors, and cURL errors, and pointing to the Start Troubleshooting and Troubleshooting the Client Area guides for broader steps.https://docs.whmcs.com/9-1/installation-guide/system-requirements/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/installation-guide/system-requirements/Lists minimum system requirements for self-hosted WHMCS installations, including supported operating system, Apache version and handlers, PHP 8.2/8.3 with required and recommended extensions and ionCube Loader versions, MySQL version and privileges, database collation, encrypted database connection variables, and recommended file and directory permissions.https://docs.whmcs.com/9-1/troubleshooting/troubleshoot-installation/troubleshooting-installation/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/troubleshooting/troubleshoot-installation/troubleshooting-installation/Indexes installation-related troubleshooting articles and links to General Troubleshooting for display and access issues and to Troubleshooting Updates for problems following a version upgrade.https://docs.whmcs.com/9-1/troubleshooting/troubleshoot-updates/troubleshooting-updates/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/troubleshooting/troubleshoot-updates/troubleshooting-updates/Index page linking to update-check, update failure, automatic-update, and post-update troubleshooting articles for the WHMCS update process.https://docs.whmcs.com/9-1/installation-guide/install-whmcs/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/installation-guide/install-whmcs/Steps through installing self-hosted WHMCS: license purchase, system requirements, uploading files, creating the MySQL database, running the browser-based install.php script, meeting the initial admin account’s password requirements, and setting permissions for configuration.php, attachments, downloads, and templates_c.https://docs.whmcs.com/9-1/installation-guide/install-on-the-command-line/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/installation-guide/install-on-the-command-line/Steps through installing or upgrading WHMCS via the command-line installer: license purchase, uploading files, supplying a configuration.php file or JSON via -c/–config, the admin.password requirements and refusal behavior, and flags like -n, -u, -i, and -s.https://docs.whmcs.com/9-1/system/updates/updating-whmcs/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/system/updates/updating-whmcs/Covers checking for and applying updates via Update Now, the automatic-update PHP requirements, unattended automatic updates for maintenance releases, the Stable/Current Version/Release Candidate/Beta Update Channel options, the Temporary Update Path and Maintenance Message settings, which files updates overwrite (language files, default templates, WHMCS-supplied modules, core files), and the tblupdatelog troubleshooting table.https://docs.whmcs.com/9-1/installation-guide/set-up-a-test-environment/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/installation-guide/set-up-a-test-environment/Walks through creating a WHMCS test environment: getting a development license, duplicating the installation and database, password-protecting the directory, updating the System URL, disabling email sending, and truncating client data tables before going live.https://docs.whmcs.com/9-1/troubleshooting/system-health/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/troubleshooting/system-health/The System Health page, at Configuration > System Health, provides an overview of the WHMCS installation and system environment status, highlights potential configuration and security issues that need attention, indicates whether updates are available for the installed version, and links to the change log and release notes. This page documents each System Health check and its recommended solution, including Automatic Update Requirements, Certificate Authority verified SSL detection, the Cloudflare proxy check, the CloudLinux MySQL extension check, the Cron HTTP Access Blocked check, Cron PHP timezone and PHP version mismatches, cURL, TLS, and OpenSSL version warnings, customising default paths, custom templates, deprecated modules that remain active and configured after an update, error reporting, event handling, invoice immutability, the obsolete invoice mutability variables in the configuration.php file, legacy Smarty tags, MySQL server configuration, OPcache status, permissions, PHP error levels, the PHP memory limit, PHP session support, the PHP version, POP cron ticket import, recommended and required PHP extensions, required PHP functions, secure TLS and SSL support in cURL, the sensitive directory check (including exposed Storage Settings directories and directories that could not be evaluated), system cron tasks, the system URL check, two-factor authentication storage encryption, and website SSL.https://docs.whmcs.com/9-1/troubleshooting/troubleshoot-the-database/unable-to-connect-errors/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/troubleshooting/troubleshoot-the-database/unable-to-connect-errors/Documents “Critical Error - Unable to connect to the database” caused by incorrect configuration.php database settings, database user permissions, a missing pdo_mysql extension, or required encrypted connection settings, with fixes for each scenario.https://docs.whmcs.com/9-1/system/updates/update-tutorials/check-for-updates/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/system/updates/update-tutorials/check-for-updates/Gives the steps to manually check for a new WHMCS version by clicking Check Now on the Update WHMCS page, and what the An update is available message indicates about the current Update Channel and system requirements.https://docs.whmcs.com/9-1/system/system-tutorials/optimize-performance/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/system/system-tutorials/optimize-performance/Gives the $disable_admin_ticket_page_counts and $disable_clients_list_services_summary configuration.php flags, lists debug logging settings to disable when not troubleshooting, and covers mail provider switching and MySQL my.cnf tuning values (max_connections, wait_timeout, sort_buffer_size, read_buffer_size, max_allowed_packet) for performance.https://docs.whmcs.com/9-1/system/updates/update-tutorials/prepare-to-update-whmcs/Mon, 01 Jan 0001 00:00:00 +0000https://docs.whmcs.com/9-1/system/updates/update-tutorials/prepare-to-update-whmcs/Lists the recommended pre-update checklist for self-hosted WHMCS installations: reviewing release notes for the target and intermediate versions, checking system requirements, protecting custom themes and order form templates with dedicated directories or override files, testing updates in a non-production environment, backing up the database and directory, and confirming MySQL permissions.