#23e -- DV360 "Malformed VAST" Rejections (7 Specific Creatives)

Priority: High Status: Partial Category: Tagging Raised by: Minh (Humology), 29 Apr 2026

Problem

DV360 is rejecting 7 specific creatives as "malformed VAST". This prevents the ads from serving through DV360 entirely.

Kevin's Assessment (Discord)

This needs more info. When and what creatives Might find something in mail chain Since it was fixed quite some time ago..

Kevin believes this was already fixed some time ago. Needs more information about which specific creatives and when the rejections occurred.

What We Know

• The VAST tag stack fixes (#23b, released 8 May) resolved some rejections
• The responsive companion ad fix (#23c, released ~12 May, PR #1877) resolved additional rejections -- VAST doesn't support truly responsive creatives
• Kevin says it was "fixed quite some time ago" -- the remaining question is whether all 7 creatives are now working

Cavai Feasibility Assessment

Can we fix this from our side? Likely already fixed.

The resolution lives in two already-released fixes:

1. #23b -- VAST tag stack fixes (HLS streaming, fallback media, ad-stitching, non-streaming bitrate) -- released 8 May
2. #23c -- Responsive companion ad auto-transform to fixed VAST sizes -- released ~12 May

The root cause was that VAST does not support truly responsive creatives, and the VAST tag stack had issues with HLS streaming, fallback media, and bitrate handling.

Open Questions

1. Are all 7 creatives now serving correctly in DV360? Need confirmation from Humology
2. If any are still rejected, which ones? Kevin needs the specific creative IDs/links
3. When were the rejections last observed? Before or after the May fixes?

Next Steps

1. Ask Humology to re-check the 7 creatives in DV360
2. If still failing, get specific creative links and error messages from DV360
3. Kevin can investigate specific creatives if we have the IDs

Related Items

• #23b (VAST tag stack fixes -- released 8 May)
• #23c (responsive companion ad fix -- released, PR #1877)
• #29 (VAST tag enhancement bundle -- released 14 May)