VAST-2.0-version-mismatch

Q: How do I fix VAST-2.0-version-mismatch?

Update the `version` attribute on ` ` to match the highest version your elements require — e.g. use `4.1` if you are using ` ` or ` ` text content.

Declared version does not match structural signals

WarningConsistencyIAB VAST 2.0 §2.1VAST 2.0 and later (all versions)

The `version` attribute on `<VAST>` claims one version (e.g., `4.1`) but the document uses elements or attributes that only exist in a different version. This causes players to either ignore those elements or reject the tag.

How to fix

Update the version attribute on <VAST> to match the highest version your elements require — e.g. use 4.1 if you are using <AdServingId> or <UniversalAdId> text content.

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Other Consistency rules

VAST-2.0-parse-errorXML parse error — document may be malformed VAST-2.0-duplicate-impressionDuplicate <Impression> URL within the same <Ad>