VAST error codes / Linear and media errors
VAST error 402: Media file timeout
Short answer: Fetching the MediaFile took longer than the player allowed.
Debug this tag now
If you only have a live URL, test it first. If the failure is in the wrapper chain, inspect each hop. Validate resolved XML when you already have the response.
What your player reported
402· Timeout of MediaFile URI.
Wording from the IAB VAST 4.3 specification error table. Players may shorten or reformat it, but the code is the same.
What it means
The media URL was reachable but the file did not download inside the player's time budget.
Common causes
- A slow CDN or oversized media file
- Bitrate or file size too high for the available bandwidth
- Throttled or geo-slow origin
How to fix it
Offer appropriately sized renditions and check `bitrate`/dimensions on each `<MediaFile>` against the target device.
VAST error codes are runtime buckets emitted by the player. They tell you where the failure happened, not which line of XML caused it. Paste the raw tag into the validator to map this code onto the exact element and rule.
Related vastlint rules
- VAST-2.0-mediafile-dimensions: <MediaFile> must have width and height attributes
Related error codes
Debug this tag now
Validate the XML, follow the wrapper chain, or check it in CI before launch:
# CLI: exits non-zero on errors, ideal for pipelines
vastlint check creative.xml