TYPO3 v10 has reached end-of-life as of April 30th 2023 and is no longer being maintained. Use the version switcher on the top left of this page to select documentation for a supported version of TYPO3.
Need more time before upgrading? You can purchase Extended Long Term Support (ELTS) for TYPO3 v10 here: TYPO3 ELTS.
In the Install tool, go to the module "Maintenance" -> "Manage languages" and update your translations. If you don't update your translations, new texts will only be displayed in English. Missing languages or translations can be added following the section Internationalization and Localization.