TYPO3 Core

While calling backend login (/typo3) I get following:

Return value of TYPO3\CMS\Core\ExpressionLanguage\RequestWrapper::getSite() must be an instance of TYPO3\CMS\Core\Site\Entity\Site or null, instance of TYPO3\CMS\Core\Site\Entity\NullSite returned

TYPO3: 9.4.0

TypoScript

// First foreign language:
[site("languageId") == 1]
    config {

        language = en
        locale_all = en_GB.utf8
        sys_language_uid = 1

    }
[global]

// Second foreign language:
[site("languageId") == 2]
    config {

        language = fr
        locale_all = fr_FR.utf8
        sys_language_uid = 2

    }
[global]

BTW: Using "sites" this TypoScript is a bit stupid ... and the correct condition is [siteLanguage("languageId") == 1]...[end]