$is_mod = $ext['type'] == 'module';

be

        $is_mod = $ext['type'] == 'extension';

Better still, have the line removed as the $is_mod variable is not used anywhere at all.

In the file includes/ui/ui_lists.inc, shouldn't the line 2213

        if ($ext['type'] == 'module' && !$ext['active'])
            $tabs[$ext['tab']] = access_string($ext['title'], true);

be

        if ($ext['type'] == 'extension' && !$ext['active'])
            $tabs[$ext['tab']] = access_string($ext['title'], true);

Also the subsequent line refers to the $ext['tab'] variable coming from $installed_extensions array that has been commented out in includes/packages.inc file in lines 128, 494, 671-672.

On a similar note, consequent to the gross changes in the extensions / plugins system in FA v2.3+, the file sql/alter2.3.php has the line 297 as part of a commented out block.