<settings.media>
<TCEforms>
<label>Image</label>
<config>
<type>inline</type>
<minitems>0</minitems>
<maxitems>1</maxitems>
<appearance type="array">
<createNewRelationLinkTitle>LLL:EXT:cms/locallang_ttc.xlf:media.addFileReference</createNewRelationLinkTitle>
<enabledControls type="array">
<delete>1</delete>
<dragdrop>1</dragdrop>
<hide>1</hide>
<info>1</info>
<localize>1</localize>
</enabledControls>
<headerThumbnail type="array">
<field>uid_local</field>
<height>45c</height>
<width>45</width>
</headerThumbnail>
<useSortable>1</useSortable>
<showAllLocalizationLink>0</showAllLocalizationLink>
<showPossibleLocalizationRecords>0</showPossibleLocalizationRecords>
<showRemovedLocalizationRecords>0</showRemovedLocalizationRecords>
<showSynchronizationLink>0</showSynchronizationLink>
</appearance>
<behaviour type="array">
<localizationMode>select</localizationMode>
<localizeChildrenAtParentLocalization>1</localizeChildrenAtParentLocalization>
</behaviour>
<foreign_field>uid_foreign</foreign_field>
<foreign_label>uid_local</foreign_label>
<foreign_match_fields type="array">
<fieldname>media</fieldname>
</foreign_match_fields>
<foreign_selector>uid_local</foreign_selector>
<foreign_selector_fieldTcaOverride type="array">
<config type="array">
<appearance type="array">
<elementBrowserAllowed></elementBrowserAllowed>
<elementBrowserType>file</elementBrowserType>
</appearance>
</config>
</foreign_selector_fieldTcaOverride>
<foreign_sortby>sorting_foreign</foreign_sortby>
<foreign_table>sys_file_reference</foreign_table>
<foreign_table_field>tablenames</foreign_table_field>
</config>
</TCEforms>
</settings.media>
Смотри лог и видим следующую ошибку
Core: Exception handler (WEB): Uncaught TYPO3 Exception: #1446996319: Configuration retrieved from FlexForm is incomplete or not of type "inline".
Само собой в ядро лезть неправильно. Поэтому нужно сделать корректировку в своем расширении. В файл ext_localconf.php добавляем следующий код:
if ((float)TYPO3_version >= 7.0) { // bugfix for inline fal images in flexforms (only after record with flexform has been saved)
$GLOBALS['TYPO3_CONF_VARS']['SYS']['formEngine']['formDataGroup']['inlineParentRecord']
[\TYPO3\CMS\Backend\Form\FormDataProvider\DatabaseEditRow::class] = array();
$GLOBALS['TYPO3_CONF_VARS']['SYS']['formEngine']['formDataGroup']['inlineParentRecord']
[\TYPO3\CMS\Backend\Form\FormDataProvider\InitializeProcessedTca::class] = array(
'depends' => array(
\TYPO3\CMS\Backend\Form\FormDataProvider\DatabaseEditRow::class,
)
);
}
После этого всё нормально работает.
Решение было найдено здесь https://forge.typo3.org/issues/71564