Companion width and height are required
<Companion> missing width or height
Short answer
<Companion> creatives need both width and height. Without them, most players cannot match the creative to a slot and will ignore the companion entirely.
Companion slots are matched by size. A `<Companion>` without `width` and `height` cannot be matched to a slot and will usually be ignored.
Why this matters in production
This rule is a strong risk signal. Tags with this issue often still parse, but they become brittle across SDKs, SSAI resolvers, and CTV environments. Ambiguous rules matter because undefined behavior shifts between vendors. Fixing them reduces the chance that two standards-compliant systems interpret the same tag differently. Affected scope: VAST 2.0 and later (all versions).
How to fix
Add width and height attributes to <Companion> matching the slot dimensions, e.g. width="300" height="250".
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