VAST-2.0-parse-error

Q: How do I fix VAST-2.0-parse-error?

Fix the XML syntax error: close all open tags, escape ` `, and `&` outside CDATA as `<`, `>`, `&`, and confirm the declared encoding matches the file encoding.

XML parse error — document may be malformed

ErrorConsistencyIAB VAST 2.0 §2VAST 2.0 and later (all versions)

The VAST document is not well-formed XML. This usually means unclosed tags, unescaped `<`/`&` characters outside CDATA, or invalid encoding. Virtually every player will reject a malformed XML document outright.

How to fix

Fix the XML syntax error: close all open tags, escape <, >, and & outside CDATA as <, >, &, and confirm the declared encoding matches the file encoding.

Invalid

<VAST version="4.0">
  <Ad id="1">
    <InLine>
      <AdTitle>My Ad & Promo</AdTitle>  <!-- & must be &amp; outside CDATA -->
    </InLine>
  </Ad>
</VAST>

Valid

<VAST version="4.0">
  <Ad id="1">
    <InLine>
      <AdTitle>My Ad &amp; Promo</AdTitle>
    </InLine>
  </Ad>
</VAST>

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Other Consistency rules

VAST-2.0-version-mismatchDeclared version does not match structural signals VAST-2.0-duplicate-impressionDuplicate <Impression> URL within the same <Ad>