Environment
Newly installed Joomla 6.0.0
How To Test
Go to System Dashboard - Manage - Plugins.
Check the status of the plugin 'Behaviour - Backward Compatibility 6' and make sure it is enabled.
Go to System Dashboard - Information - System Information.
Check the setting 'Joomla Backward Compatibility Plugin'.
Expected Result
Enabled
Actual Result
Disabled
Resolution
Line 317 of administrator/components/com_admin/src/Model/SysinfoModel.php in Joomla 6.0.0 is identical in Joomla 5.4.0:
'compatpluginenabled' => PluginHelper::isEnabled('behaviour', 'compat'),
Change the folder from compat to compat6:
'compatpluginenabled' => PluginHelper::isEnabled('behaviour', 'compat6'),
Report
First reported by @gws in the Joomla! Forum topic backwards compatability plugin