Deprecation: #88569 - Locales::initialize() in favor of regular singleton instance

See forge#88569


The method TYPO3\CMS\Core\Localization\Locales::initialize() has been marked as deprecated. It was a workaround to re-initialize the Singleton Instance of the PHP class Locales for user-defined locales, which were loaded by an extensions' ext_localconf.php.

Locales is now initialized only when needed, and not during the early bootstrap process, making this functionality obsolete, as this is taken care of within the regular constructor.


Calling TYPO3\CMS\Core\Localization\Locales::initialize() will trigger a PHP E_USER_DEPRECATED error.

Affected Installations

Any TYPO3 installation with a third-party extension calling Locales::initialize() directly.


Replace the function call by a regular GeneralUtility::makeInstance(Locales::class); or use Dependency Injection (Constructor Injection or ObjectManager) to fetch an instance of the Locales class.