VAST error code
200 — Trafficking error
What the spec says
The player received an ad type it was not expecting, so the creative could not be used in the slot it was served into.
What actually causes it
- A non-linear or companion creative delivered into a linear video slot, or the reverse.
- An audio creative served to a video placement.
- A placement configured for one format in the ad server and another in the player.
How to fix it
Compare the creative type in the ad server against what the placement expects. This is a trafficking configuration mismatch rather than a fault in the tag itself, so it is fixed in the setup, not the XML.
To see whether a tag would hit this before it runs, paste it into the VAST validator. It reads the XML and reports the conditions that map to this code.
Related codes
Code definitions from the IAB Tech Lab VAST 4.3 specification. Causes and fixes are practitioner guidance, last verified July 2026.