What to Check After Upgrading to Joomla 6
Confirm the installed Joomla version
Sign in to Administrator and verify that the site reports the intended Joomla 6 release. Do not assume a returned login screen proves every update step completed. If the reported version is unexpected, stop further changes and review the update result and logs.
Check the Joomla database structure
Open System → Maintenance → Database and look for schema warnings. If Joomla reports core database inconsistencies, use the supported Update Structure action and investigate any SQL error that remains. Do not manually invent missing core columns or schema-version records.
Review PHP and server health
Confirm the site is running on a Joomla 6-supported PHP version and that required PHP modules remain available. Review PHP and web-server logs for new fatal errors, warnings, memory failures, or extension exceptions that may not be obvious from the frontend.
Test Administrator and frontend workflows
Create or edit representative content, verify menus and modules, test login and logout, and inspect key frontend layouts at desktop and mobile widths. Check template overrides and custom layouts closely because a site can appear generally healthy while a specific view is broken.
Test third-party extensions and integrations
Exercise forms, search, scheduled tasks, email delivery, APIs, payment or membership workflows, backups, security tools, and other site-specific extensions. Confirm extension versions and update sites are still correct. A successful core update does not certify third-party functionality.
Clear caches and check background work
Clear Joomla and relevant external caches when appropriate, then confirm scheduled tasks, queue processing, cron jobs, command-line scripts, and cache warmers still run under the production PHP environment. Check that jobs are not silently using a different command-line PHP version.
Keep the rollback backup until verification is complete
Do not delete the pre-upgrade backup as soon as the homepage loads. Joomla does not support downgrading after an upgrade; if a serious problem cannot be corrected safely, the known recovery path is restoration of the complete pre-upgrade state.
Need More Help with Joomla?
Still having trouble? Open a support ticket with QuantaCade Support and we'll be happy to help where we can.
Support priority is given to QuantaCade products, services, and customers. However, we're also happy to assist fellow Joomla users with general Joomla questions and troubleshooting when possible.
QuantaCade is an independent Joomla extension developer and is not official Joomla support. Some issues involving third-party extensions, hosting environments, server configurations, or other systems outside our development control may be beyond what we're able to resolve.