07.10.2026-2
Each <Ad> of a /v1alpha2 VAST response now carries an <Error> URL. If the player cannot play the ad, it can now tell us.
What changed
Section titled “What changed”The <Error> URL has the [ERRORCODE] macro in its error_code parameter. The ets parameter is not needed on an error. The server counts the error by its code. An error is never a play: we do not bill it and we do not count it as delivery.
What to do
Section titled “What to do”Firing the <Error> URL is optional. To report an ad that cannot play, fire its <Error> URL one time with the VAST error code in place of the macro. Do not fire the <Impression> or <Tracking> URLs of that ad.