VAST error codes / NonLinear and companion
VAST error 503: No supported NonLinear resource
Short answer: No overlay resource type the player supports.
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
503· Couldn’t find NonLinear resource with supported type.
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
Resources were present but none had a type the player can render.
Common causes
- Only resource types the player cannot display
- Wrong `creativeType` on the resource
How to fix it
Provide a `<NonLinear>` resource in a supported type with a correct `creativeType`.
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-nonlinear-resource: InLine <NonLinear> must contain at least one StaticResource, IFrameResource, or HTMLResource
Related error codes
- VAST error 500: General NonLinearAds error
- VAST error 501: NonLinear dimensions do not fit
- VAST error 502: Cannot fetch NonLinear resource
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