TYPO3 Core

This issue seems to occur on TYPO3 12.0.0-dev (latest master) (not TYPO3 11 as far as I can see)

with the admin panel enabled:

config.admPanel = 1

the frontend is broken, and it shows the error

(1/1) TypeError
TYPO3\CMS\Extbase\Utility\LocalizationUtility::translate(): Argument #1 ($key) must be of type string, bool given, called in /Users/riccardo/TYPO3-dists/typo3_master/typo3/sysext/fluid/Classes/ViewHelpers/TranslateViewHelper.php on line 184

Attached: the screenshot of the full message

I could be wrong, but at one point of the message I've read:

[...]
at TYPO3Fluid\Fluid\View\AbstractTemplateView->renderPartial('Modules/Item', null, array('module' => ....
[...]

I think it refers to

/sysext/adminpanel/Resources/Private/Partials/Modules/Item.html

where I see multiple lines like:

<f:translate key="LLL:EXT:adminpanel/Resources/Private/Language/locallang.xlf:settings.label" languageKey="{languageKey}"/>