How to Find Extensions Blocking a Joomla Upgrade

Start with the Extensions section of the Pre-Update Check

1. Go to System → Update → Joomla.
2. Open the Pre-Update Check for the target Joomla version.
3. Review the Extensions section and note every extension that is not clearly reported as compatible.
4. Record the extension name, type, installed version, and the compatibility status Joomla shows.

Do not focus only on components. Plugins, modules, packages, libraries, templates, files, and language-related packages can also affect an upgrade.

Match each warning to the actual installed extension

Go to System → Manage → Extensions and search for the extension reported by the Pre-Update Check. Packages can install several related items, so you may see a component plus multiple plugins, modules, or libraries from the same vendor.

For each questionable extension, record:

• extension name and type;
• installed version;
• enabled or disabled state;
• author/vendor;
• package relationships where identifiable;
• whether the extension is still needed;
• whether the vendor currently supports the target Joomla version.

An old disabled extension should not automatically be considered harmless. Its files, autoloaded libraries, installer plugins, or package dependencies can still create conflicts.

Update extensions before the Joomla upgrade when the vendor requires it

Open System → Update → Extensions and install current releases that are specifically intended to run on both your current Joomla version and the target version. Some vendors publish bridge releases for major Joomla migrations; skipping that intermediate extension version can leave the wrong database schema or migration state.

After updating, return to the Joomla Pre-Update Check. If the status changes to compatible, you have useful evidence that the extension update metadata now recognizes the target Joomla version.

If no update appears, refresh the extension update information and check System → Manage → Update Sites for a disabled, broken, or outdated update site. A missing update notification does not prove that your installed version is current.

Investigate extensions with missing compatibility information

When Joomla reports that compatibility information is unavailable, check the extension developer's current documentation directly. Look for an explicit statement covering both the target Joomla major version and the PHP version you intend to use.

If the extension is abandoned, has not been updated for a long time, or the developer does not support the target Joomla release, plan to replace or remove it before upgrading. For business-critical functionality, identify the replacement and migrate data on staging before touching production.

Use staging to isolate the extension that actually breaks the upgrade

The Pre-Update Check can warn about risk, but a staging copy tells you what actually happens to your site.

1. Create a full production backup and restore it to a staging environment.
2. Match the production PHP and database environment first, then apply the target upgrade requirements.
3. Update Joomla and third-party extensions through their documented migration paths.
4. If the upgrade fails, record the first fatal error or installer error before changing anything else.
5. Match the error path, class name, plugin name, or database table to the installed extension inventory.
6. Restore staging to the clean pre-upgrade snapshot before testing a different removal/disable scenario.

Changing several extensions at once makes it difficult to identify which change fixed the upgrade. Isolate one suspected blocker at a time when practical.

Remove a blocker only with a safe data plan

If an extension must be removed before the Joomla upgrade, confirm what its uninstall process deletes. Some extensions remove their own database tables and stored content. Export or preserve data before uninstalling anything that matters.

After removing or replacing the incompatible extension, clear Joomla's cache, refresh extension update information, rerun the Pre-Update Check, and repeat the staging upgrade from a clean snapshot. When the staging upgrade completes, test all major frontend and Administrator workflows before making the same changes in production.