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How to disable the Behaviour – Backward Compatibility plugin in Joomla 5

Prior to upgrading from Joomla 5 to Joomla 6, the Behaviour – Backward Compatibility plugin must be disabled. The Behaviour – Backward Compatibility 6 plugin is installed and enabled by default in Joomla 5.4 but it doesn’t perform any actions as its presence ensures that when the site is upgraded to Joomla 6, the updated code can run immediately, and any third-party extensions requiring the plugin to be enabled in Joomla 6 will not cause the update to fail.

To read more about the different role in both Behaviour – Backward Compatibility vs Behaviour – Backward Compatibility 6 plugins, head here

To disable the Behaviour – Backward Compatibility plugin,

  • Navigate to System > under Manage panel
  • Click Plugins
  • Then look for the “Behaviour – Backward Compatibility“
  • On the Status column, click a check icon to disable it and that’s it

See reference screenshot.

Now, if the site fails to load and showing errors, cannot access to backend site after disabling it in Joomla 5. Don’t panic, simply re-enable the plugin to restore functionality, bring the site back online and troubleshoot the errors. It should be investigated and resolved while still running Joomla 5, before attempting the upgrade Joomla 6 again.

Here’s how to re-enable the “Behaviour – Backward Compatibility” without accessing to Joomla site back end. All you need is the access to phpMyAdmin.

  • Open the database in phpMyAdminGo to the table #_extensions
  • Find the row with the name “plg_behaviour_compat”
  • In the “enabled” column, change the value 0 to 1
  • Now, the “Behaviour – Backward Compatibility” is enabled again

See reference screenshot.

Now you got the “Behaviour – Backward Compatibility” back, don’t try to disable this plugin again until you find out if the third party extensions are compatible with Joomla 6 or not (with or without the backward compatibility plugin).