VASTlint

VAST error codes / NonLinear and companion

VAST error 604: No supported companion resource

Short answer: No companion 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

604 · Couldn’t find Companion 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 unsupported resource types
  • Wrong `creativeType` on the resource

How to fix it

Provide a companion 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

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

Further reading