VAST Error 102: VAST version not supported

The player received a VAST version it does not support or did not ask for. In operations, this usually shows up when the ad response declares a version outside the player's supported range or omits the expected version details.

This is the kind of issue that is easiest to solve when the investigation starts from the right evidence path. VAST Inspector is usually the fastest first step because it confirms whether the response, wrapper chain, or media selection behaves the way the player expects.

This often happens during partner onboarding, player upgrades, or when a supply-side platform ignores the version expectations in the request.

The most common causes are the bidder or ad server returns a newer VAST version than expected, the player only supports older VAST versions, and the response does not declare version cleanly. Teams often treat the visible error as the root problem, but in practice the real issue may sit earlier in the wrapper path, in the creative package, or in the environment assumptions around the request.

That is why it helps to compare a failing request against a known-good example. Once you know whether the difference is structural, timing-related, or environment-specific, escalation becomes much faster and cleaner.

VAST Inspector should be the first stop for this class of issue. From there, move into VAST Error Code Explainer to narrow the failure further.

A useful investigation should end with concrete evidence: the failing tag or asset, the exact point where the player behavior diverged, and the partner or configuration change most likely responsible. That turns a generic player code into an actionable support ticket or launch fix.

Confirm the version in the response, compare it with the target player or SDK support level, and adjust either the request settings or the returned VAST version.