---
title: "Deprecation: #84273 - Protected methods and properties in FileSystemNavigationFrameController"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:deprecation-84273"
source: "Changelog/9.2/Deprecation-84273-ProtectedMethodsAndPropertiesInFileSystemNavigationFrameController.rst"
typo3-version: "9.2"
typo3-major: 9
type: "deprecation"
issue: 84273
forge: "https://forge.typo3.org/issues/84273"
tags: ["Backend", "PHP-API", "PartiallyScanned"]
rendered: "2026-09-19T12:12:50+00:00"
---

# Deprecation: #84273 - Protected methods and properties in FileSystemNavigationFrameController {#deprecation-84273}

See [forge#84273](https://forge.typo3.org/issues/84273)

## Description {#description}

This file is about third party usage (consumer that call the class as well as
signals or hooks depending on it) of `\TYPO3\CMS\Backend\Controller\FileSystemNavigationFrameController`.

A series of class properties have been set to protected.
They will throw deprecation warnings if called public from outside:

-   \[not scanned\] `$content`
-   `$foldertree`
-   `$currentSubScript`
-   `$cMR`

All methods not used as entry points by `\TYPO3\CMS\Backend\Http\RouteDispatcher` will be
removed or set to protected in v10 and throw deprecation warnings if used from a third party:

-   `initPage()`
-   \[not scanned\] `main()`
-   \[not scanned\] `init()`

## Impact {#impact}

Calling one of the above methods or accessing one of the above properties on an instance of
`FileSystemNavigationFrameController` will throw a deprecation warning in v9 and a PHP fatal in v10.

## Affected Installations {#affected-installations}

The extension scanner will find most usages, but may also find some false positives. The most
common property and method names like `$content` are not registered and will not be found
if an extension uses that on an instance of `FileSystemNavigationFrameController`. In general all extensions
that set properties or call methods except `mainAction()` are affected.

## Migration {#migration}

In general, extensions should not instantiate and re-use controllers of the core. Existing
usages should be rewritten to be free of calls like these.