VAST-4.0-universaladid-idregistry
VAST-4.0-universaladid-idregistry
<UniversalAdId> must have an idRegistry attribute
ErrorRequired fieldsIAB VAST 4.0 §2.3.4VAST 4.0, 4.1, 4.2, and 4.3
Short answer
<UniversalAdId> requires an idRegistry attribute that names the registry that issued the identifier (e.g., ad-id.org). Without it the ID is unresolvable.
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. 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 4.0, 4.1, 4.2, and 4.3.
How to fix
Add the idRegistry attribute to <UniversalAdId> naming the issuing registry, e.g. idRegistry="ad-id.org".
Invalid
<UniversalAdId></UniversalAdId>Valid
<UniversalAdId idRegistry="ad-id.org">ADID123</UniversalAdId>Check your VAST tag for
VAST-4.0-universaladid-idregistry and other issues instantly.Open the VAST tag validator →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-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>VAST-2.0-inline-impression<InLine> must contain at least one <Impression>