Invalid XML Structure
xml
The XML document is well-formed at the token level but its structure violates a constraint the parser enforces.
Q-9-4 — Invalid XML Structure
The XML document is well-formed at the token level but its structure violates a constraint the parser enforces.
What this means
Q-9-4 is the catch-all the XML parser uses when the input is
syntactically well-formed (all tags balanced, no stray
characters) but the structure breaks an XML rule the parser
cares about — for instance, content appearing where only
declarations are allowed, or a processing instruction outside
its permitted position. The message names the specific
constraint that failed.
Why this happens
Common causes:
- Content before the XML declaration.
<?xml version="1.0"?>must be the very first thing in the document. - A namespace prefix used without being declared.
- A construct that is legal XML in general but illegal in the position it appears in.
How to fix
Read the message — it names the specific constraint. The fix usually has the same shape as the constraint: move the declaration earlier, declare the namespace, or remove the out-of-place construct.