vastlint

VAST-4.1-adservingid-present

<InLine> must contain <AdServingId> (VAST 4.1+)

ErrorRequired fieldsIAB VAST 4.1 §2.3VAST 4.1, 4.2, and 4.3

Starting with VAST 4.1, `<AdServingId>` is a required element inside `<InLine>`. It carries an opaque unique identifier assigned by the ad server for event deduplication and reconciliation.

How to fix

Add <AdServingId>unique-id-per-response</AdServingId> inside <InLine>, generating a fresh UUID for every ad response.

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