Version 4.1.2

applications/core/modules/admin/members/groups.php

@@ -165,7 +165,7 @@ class _groups extends \IPS\Dispatcher\Controller
 		$form = new \IPS\Helpers\Form( ( !$group->g_id ? 'groups_add' : $group->g_id ) );
 		foreach ( $extensions as $k => $class )
 		{
-			$form->addtab( 'group__' . $k );
+			$form->addTab( 'group__' . $k );
 			$class->process( $form, $group );
 		}