vastlint
VAST-4.1-tracking-event-value

VAST-4.1-tracking-event-value

Tracking event attribute not in the valid set for this VAST version

ErrorValuesIAB VAST 4.1 §2.4.1VAST 4.1, 4.2, and 4.3

Short answer

The event attribute on <Tracking> must be one of the valid values for the declared VAST version. An unrecognised event name will be silently ignored by players.

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. Value-format rules tend to fail at the moment a player interprets a field such as duration, skipoffset, bitrate, or versioning. They are especially painful because the XML can look valid at a glance. Affected scope: VAST 4.1, 4.2, and 4.3.

How to fix

Replace the invalid event value with one from the allowed set for your declared VAST version — refer to the spec table for your version.

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Other Values rules

VAST-2.0-duration-format<Duration> value does not match HH:MM:SS[.mmm] formatVAST-2.0-mediafile-delivery-enum<MediaFile> delivery must be "progressive" or "streaming"VAST-3.0-skipoffset-formatLinear skipoffset does not match HH:MM:SS[.mmm] or n% formatVAST-3.0-progress-offset-formatTracking progress offset does not match required formatVAST-3.0-skip-event-no-skipoffsetskip tracking event present but Linear has no skipoffset attributeVAST-3.0-minmaxbitrate-pair<MediaFile> must have both minBitrate and maxBitrate or neitherVAST-3.0-bitrate-conflict<MediaFile> has both bitrate and minBitrate/maxBitrateVAST-4.0-tracking-event-removedfullscreen/exitFullscreen tracking events were removed in VAST 4.0