TYPO3 Core

Probably due to language label renaming (removal of "ll_" prefixes) for TYPO3 10 in EXT:felogin now the translations for EXT:felogin for TYPO3 9 (and probably below) are broken.

Example of code in EXT:felogin/Classes/Controller/FrontendLoginController.php line 296 in TYPO3 9.5.9:

$markerArray['###DATA_LABEL###'] = htmlspecialchars($this->pi_getLL('ll_enter_your_data'));

But the translation server now serves this and other EXT:felogin labels in for example typo3conf/l10n/de/felogin/Resources/Private/Language/de.locallang.xlf without the "ll_" prefix:

<trans-unit id="enter_your_data" approved="yes">
    <source>Username or email address</source>
    <target state="translated">Benutzername oder E-Mail-Adresse</target>
</trans-unit>

This results in many labels remaining always english in all translated languages and you have mixed languages in the frontend.