When installing entity_browser, inline_entity_form, lightning_media, lightning_media_image I had no problems.
But later on, the config import failed with the mentioned error.
After I applied the schema change from the merge request, the config import works again.
RTBC
I have developed a patch.
Drupal::languageManager()->getCurrentLanguage()->getId() gets the current language code of the website. This can be passed to drupalSettings.googleTranslatorElement and used as pageLanguage for the new TranslateElement.
It would also be possible to leave pageLanguage undefined. Then google tranlsate will automatically set the source language.