vastlint
SIMID-1.0-simid-mediafile-required

SIMID-1.0-simid-mediafile-required

Linear SIMID ad must include a video/audio <MediaFile> alongside the interactive creative

ErrorLinearIAB SIMID 1.0 §3.4

Short answer

A SIMID `<InteractiveCreativeFile>` in a `<Linear>` ad must always be accompanied by at least one standard `<MediaFile>` element. SIMID §3.4 is explicit: "SIMID cannot be used to decide which media to show on the client pre-impression. This is because the media file must be present alongside the SIMID creative and delivered via the VAST MediaFile node." Without a `<MediaFile>`, the player has no media to play. Players that do not support SIMID will also have no fallback, resulting in an empty ad slot.

Why this matters in production

This is usually an interaction blocker. When a SIMID error reaches error level, the creative iframe or handshake typically never completes. Linear SIMID issues affect the handshake between the primary video creative and the interactive layer. When these break, the ad often falls back to plain video or fails interaction entirely.

A SIMID <InteractiveCreativeFile> in a <Linear> ad must always be accompanied by at least one standard <MediaFile> element. SIMID §3.4 is explicit: "SIMID cannot be used to decide which media to show on the client pre-impression. This is because the media file must be present alongside the SIMID creative and delivered via the VAST MediaFile node." Without a <MediaFile>, the player has no media to play. Players that do not support SIMID will also have no fallback, resulting in an empty ad slot.

How to fix

Add a <MediaFile> video element (MP4 recommended) to <MediaFiles> alongside the <InteractiveCreativeFile>.

Broader troubleshooting

If this rule is one part of a bigger SIMID delivery issue, start with the SIMID troubleshooting guide for a checklist covering iframe URLs, HTTPS, fallback media, and player support.

Invalid

<MediaFiles>
  <!-- no <MediaFile> — invalid per SIMID §3.4 -->
  <InteractiveCreativeFile type="text/html" apiFramework="SIMID">
    <![CDATA[https://example.com/creative.html]]>
  </InteractiveCreativeFile>
</MediaFiles>

Valid

<MediaFiles>
  <MediaFile delivery="progressive" type="video/mp4" width="1280" height="720">
    <![CDATA[https://example.com/ad.mp4]]>
  </MediaFile>
  <InteractiveCreativeFile type="text/html" apiFramework="SIMID">
    <![CDATA[https://example.com/creative.html]]>
  </InteractiveCreativeFile>
</MediaFiles>
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Other Linear rules

SIMID-1.0-simid-type-required<InteractiveCreativeFile apiFramework="SIMID"> must have type="text/html"SIMID-1.0-simid-url-empty<InteractiveCreativeFile apiFramework="SIMID"> must contain a non-empty URLSIMID-1.0-simid-url-https<InteractiveCreativeFile apiFramework="SIMID"> URL must use HTTPSSIMID-1.0-simid-variable-duration-valuevariableDuration must be "true" when present on a SIMID InteractiveCreativeFile
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