Missing Required Element
xml
A CSL element is missing a child element that its schema requires.
Q-9-9 — Missing Required Element
A CSL element is missing a child element that its schema requires.
What this means
Several CSL elements require specific children. <cs:style>
requires <cs:citation> and <cs:info>; <cs:citation>
requires <cs:layout>. This error fires when one of those
required children is missing from the parent. The message names
both the parent and the missing child.
Why this happens
Common causes:
- A hand-edited style where the child was deleted by mistake.
- A style copied from a partial snippet that did not include all the required pieces.
- A misunderstanding of which children are required vs optional — many CSL elements look complete on inspection while still missing a required piece.
How to fix
Add the missing child element inside the parent named in the message. The CSL specification documents the required children for every element.