Problem

When visiting the API Portal (Joomla) Update section, the following error is displayed:

An error has occurred.
Could not load root metadata.

This error prevents applying an upgrade to Joomla.

Solution

As a temporary workaround, modify the following file:

• libraries/src/Updater/Updater.php

Locate line 263:

$update_result = $adaptor->findUpdate($updateSite);

Change it to:

$update_result = false;

Save the file and retry the update process.

Note: This is a temporary fix and should be reverted once the root cause is resolved in Joomla’s official codebase.