VAST-3.0-progress-offset-format
VAST-3.0-progress-offset-format
Tracking progress offset does not match required format
WarningValuesIAB VAST 3.0 §2.4.1VAST 3.0, 4.0, 4.1, 4.2, and 4.3
Short answer
The offset attribute on a progress <Tracking> element must be a valid timecode (HH:MM:SS[.mmm]) or percentage (n%).
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. 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 3.0, 4.0, 4.1, 4.2, and 4.3.
How to fix
Set the offset attribute on <Tracking event="progress"> to a valid timecode (HH:MM:SS) or percentage (n%).
Check your VAST tag for
VAST-3.0-progress-offset-format and other issues instantly.Open the VAST tag validator →Other Values rules
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