[Bug] Persistent "Failed to save" error after adding Video or Review sections

I want the "Failed to save" (저장에 실패했습니다) bug to be fixed. It occurs when adding specific sections like "Video with Text (Inverted)" and "Reviews" (후기). Even after deleting the problematic section, the editor remains in a state where saving is impossible until a history restoration is performed. This is critical because it disrupts the workflow and makes users afraid to add new sections.