Removing "back to previous" link it doesn't work when typing an URL

main/document/downloadfolder.inc.php

@@ -22,7 +22,7 @@ if (empty($document_data)) {
 //a student should not be able to download a root shared directory
 if (($path == '/shared_folder' || $path=='/shared_folder_session_'.api_get_session_id()) && (!api_is_allowed_to_edit() || !api_is_platform_admin())){		
 	echo '<div align="center">';
-	Display::display_error_message(get_lang('NotAllowedClickBack').'<br /><br /><a href="'.$_SERVER['HTTP_REFERER'].'">'.get_lang('BackToPreviousPage').'</a><br />', false);
+	Display::display_error_message(get_lang('NotAllowedClickBack'));
 	echo '</div>';
 	exit;
 }

main/inc/lib/main_api.lib.php

@@ -2381,7 +2381,8 @@ function api_not_allowed($print_headers = false) {
 	                </style>';
     }
     
-    $msg = Display::return_message(get_lang('NotAllowedClickBack').'<br /><br /><a href="'.$_SERVER['HTTP_REFERER'].'">'.get_lang('BackToPreviousPage').'</a><br />', 'error', false);
+    //$msg = Display::return_message(get_lang('NotAllowedClickBack').'<br /><br /><a href="'.$_SERVER['HTTP_REFERER'].'">'.get_lang('BackToPreviousPage').'</a><br />', 'error', false);
+    $msg = Display::return_message(get_lang('NotAllowedClickBack'), 'error', false);
     $msg = Display::div($msg, array('align'=>'center'));
 	$tpl->assign('content', $msg);