Deprecation: #86179 - Protected render() method in BackendController

See Issue #86179

Description

Method TYPO3\CMS\Backend\Controller\BackendController->render() has been set from public to protected and should not be called any longer.

Impact

Calling the method from an external object triggers a PHP E_USER_DEPRECATED error.

Affected Installations

This internal method is usually not called by extensions directly. Since the method name is so generic, the extension scanner is not configured to search for usages, it would trigger far too many false positives.

Migration

Use route target main instead that calls method mainAction and returns a proper PSR-7 Response object.