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VAST-2.0-json-escaped

VAST-2.0-json-escaped

Document is JSON-escaped, so attribute quotes are not real XML quotes

ErrorConsistencyJSONVAST 2.0 and later (all versions)

Short answer

The <VAST version> quotes are still JSON escapes (version=\"3.0\"). A player reading those bytes does not see the attributes. vastlint unescapes the document before the other checks and reports this once, instead of a pile of missing-attribute errors.

Why this matters in production

This rule is usually a delivery blocker. Many players, SDKs, and ad servers will discard the response or skip the affected creative once this condition is hit. Consistency rules catch documents that technically contain the right pieces but combine them in ways that produce conflicting signals for downstream systems. Affected scope: VAST 2.0 and later (all versions).

How to fix

Unescape the JSON string before linting or serving it. version=\"3.0\" and literal \n have to become version="3.0" and real newlines. vastlint already lints the unescaped document.

Invalid

<VAST version=\"3.0\">

Valid

<VAST version="3.0">
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Other Consistency rules

VAST-2.0-parse-errorXML parse error — document may be malformedVAST-2.0-html-display-tagInput is an HTML display ad tag, not a VAST documentVAST-2.0-version-mismatchDeclared version does not match structural signalsVAST-2.0-duplicate-impressionDuplicate <Impression> URL within the same <Ad>VAST-4.1-verification-duplicate-vendor<AdVerifications> contains duplicate vendor identifiers