VAST-2.0-mediafile-delivery
VAST-2.0-mediafile-delivery
<MediaFile> must have a delivery attribute
ErrorRequired fieldsIAB VAST 2.0 §2.4.1VAST 2.0 and later (all versions)
Short answer
Every <MediaFile> must declare how it is delivered via the delivery attribute. The valid values are progressive (HTTP download) and streaming (live stream protocol such as HLS/DASH).
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 2.0 and later (all versions).
How to fix
Add delivery="progressive" for HTTP-served files (MP4, WebM) or delivery="streaming" for live protocols (HLS, DASH).
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VAST-2.0-mediafile-delivery and other issues instantly.Validate a tag →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>