TYPO3 Core

Typoscript Setup:

        30 = TYPO3\CMS\Frontend\DataProcessing\MenuProcessor
        30 {
            special = language
            special.value = auto
            as = langmenu
            dataProcessing {
                10 = TYPO3\CMS\Frontend\DataProcessing\FilesProcessor
                10 {
                    references.fieldName = media
                }
            }
        }

The "auto" config is not taken care of in TYPO3\CMS\Frontend\DataProcessing\Menuprocessor->prepareLevelLanguageConfiguration().
There should be a condition checking the conf and passing the enabled language uids instead.

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/58576