I'm not sure if old check of $group_elements['background_image'] and $group_elements['background_video'] for empty string is ever valid or should be preserved for a historical reason e.g. to make layouts made with previous versions work correctly.
However, I decided to change check here to is_numeric instead of comparison with empty string to better reflect actual expectation of a media ID. Advice on this matter is welcome from anyone who knows the module architecture well.
iamweird → created an issue.
Probably this issue is obsolete since 🐛 InvalidArgumentException: Invalid ID provided for the "media" entity Active already changed same lines as patch from #2. Can anyone provide steps to reproduce this issue?
Rerolled over 4.x-dev.
iamweird → created an issue.