TYPO3 Core

If I try to save a sys_category in TYPO3 8.6 with selected language "all" (-1) it throws an error.

There is no problem with saving the record in an other language.

The problem was not presented in TYPO3 8.5, and occurs on every Record witch have a field configured as "group".

On other records you can save with language "all". But if you try to change back to default or any other language, it falls back to "all". (i.e. file_colection)

The error message:

Argument 3 passed to TYPO3\CMS\Core\DataHandling\Localization\DataMapProcessor::synchronizeFieldValues() must be of the type array, null given, called in /opt/T3src/TYPO3.CMS_8.x/typo3/sysext/core/Classes/DataHandling/Localization/DataMapProcessor.php on line 253