TYPO3 Core

The synchronization process will fail for synchronizing inline relations within inline relations when there are more than one language which should be synchronized from default or source language. Following error occures:

#1486233164: Child record was not processed

TCA of the main object:

[...]
'columns' => [
    'products' => [
        'exclude' => false,
        'label' => 'LLL:EXT:my_ext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_productwrapper.products',
        'config' => [
            'type' => 'inline',
            'foreign_table' => 'tx_myext_domain_model_product',
            'foreign_field' => 'productwrapper',
            'foreign_sortby' => 'sorting',
            'maxitems' => 9999,
            'appearance' => [
                'collapseAll' => true,
                'levelLinksPosition' => 'top',
                'showSynchronizationLink' => 1,
                'showPossibleLocalizationRecords' => 1,
                'showAllLocalizationLink' => 1,
                'useSortable' => true,
                'expandSingle' => 1,
                'enabledControls' => [
                    'sort' => true,
                    'delete' => true,
                    'hide' => true,
                    'localize' => true,
                    'dragdrop' => true,
                ],
            ],
        ],
    ],
]

TCA of inline element:

'columns' => [
    'images' => [
        'exclude' => false,
        'label' => 'LLL:EXT:my_ext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_product.images',
        'config' => \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::getFileFieldTCAConfig(
            'images',
            [
                'appearance' => [
                    'createNewRelationLinkTitle' => 'LLL:EXT:frontend/Resources/Private/Language/locallang_ttc.xlf:images.addFileReference',
                    'collapseAll' => true,
                ],
                'behaviour' => [
                    'allowLanguageSynchronization' => true,
                ],
                'foreign_types' => [
                    '0' => [
                        'showitem' => '
                                --palette--;LLL:EXT:lang/locallang_tca.xlf:sys_file_reference.imageoverlayPalette;imageoverlayPalette,
                                --palette--;;filePalette',
                    ],
                    \TYPO3\CMS\Core\Resource\File::FILETYPE_TEXT => [
                        'showitem' => '
                             --palette--;LLL:EXT:lang/locallang_tca.xlf:sys_file_reference.imageoverlayPalette;imageoverlayPalette,
                             --palette--;;filePalette',
                    ],
                    \TYPO3\CMS\Core\Resource\File::FILETYPE_IMAGE => [
                        'showitem' => '
                            --palette--;LLL:EXT:lang/locallang_tca.xlf:sys_file_reference.imageoverlayPalette;imageoverlayPalette,
                            --palette--;;filePalette',
                    ],
                ],
                'maxitems' => 10,
            ],
            $GLOBALS['TYPO3_CONF_VARS']['GFX']['imagefile_ext']
        ),
    ],
]