VASTlint
Validate
VAST-4.1-universaladid-idvalue-removed

UniversalAdId idValue was removed in VAST 4.1

<UniversalAdId> idValue attribute was removed in VAST 4.1

WarningRequired fieldsIAB VAST 4.1 §2.3.4VAST 4.1, 4.2, and 4.3

Short answer

VAST 4.0 stored the identifier on idValue. VAST 4.1 removed that attribute. If the document declares 4.1+, put the ID in the element text and keep idRegistry.

The `idValue` attribute was replaced by element text content in VAST 4.1. If your tag targets 4.1+ players, use element text content instead.

Why this matters in production

This rule is a strong risk signal. Tags with this issue often still parse, but they become brittle across SDKs, SSAI resolvers, and CTV environments. Required-field failures usually stop validation early because the platform cannot determine the basic shape of the ad, the creative metadata, or the mandatory tracking payload. Affected scope: VAST 4.1, 4.2, and 4.3.

How to fix

Remove the idValue attribute and place the ad identifier as the text content of <UniversalAdId> instead.

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Other Required fields rules

VAST-2.0-root-elementRoot element must be <VAST>VAST-2.0-root-version<VAST> must have a version attributeVAST-2.0-root-version-valueVAST version attribute must be a recognised version stringVAST-2.0-root-has-ad-or-error<VAST> must contain at least one <Ad> or <Error>VAST-4.0-wrapper-root-error<VAST> root contains both <Ad> and <Error> elements (invalid per VAST 4.0)VAST-2.0-ad-has-inline-or-wrapperEach <Ad> must contain exactly one <InLine> or <Wrapper>VAST-2.0-inline-adsystem<InLine> must contain <AdSystem>VAST-2.0-inline-adtitle<InLine> must contain <AdTitle>