Gemini-omni-flash-preview: video edit fails during POLLING with malformed "blobstore:///genai-api/blobref/..." URI (distinct from the July 28 regression)

Gemini API
1

I’m hitting a 400 error on gemini-omni-flash-preview via the Interactions API that doesn’t match the known July 28 regression (Omni Flash 400 errors with video) — that one returns a generic “BadRequestError: 400 invalid_request” at request time. Mine is different: the interaction is created successfully, runs for a while, and then fails during POLLING with a malformed internal file URI.

Request shape (POST /v1beta/interactions):

  • model: gemini-omni-flash-preview
  • input: 1-2 reference images + 1 uploaded video (via Files API) + text prompt
  • response_modalities: [“video”]
  • background: true
  • generation_config.video_config.task: “reference_to_video” (added per the fix suggested in Gemini-omni-flash-preview: video + image input returns 400 invalid_request — did NOT resolve this specific error)

What happens:

  1. POST /v1beta/interactions succeeds, returns an interaction ID, status starts as in_progress.
  2. Polling GET /v1beta/interactions/{id} returns status updates for a while.
  3. Eventually a poll returns HTTP 400:

{“error”:{“message”:“Unsupported file uri: blobstore:///genai-api/blobref/global::000050ecbb30026d:000002fa:2:000050ecbb30026d:0000000000000001…”,“code”:“invalid_request”}}

Note the URI has an empty authority component (blobstore:///, three slashes) — looks like a malformed internal file reference being returned by the backend itself, not something I’m sending.

Reproducibility:

  • Happens consistently across multiple attempts.
  • Happens identically with and without the reference images (so it’s not specific to the image inputs).
  • Input video: mp4, 16:9, 480p.

Searched extensively (this forum, GitHub across all google-genai SDKs, general web) and found no existing report matching this exact “blobstore” error string — seems distinct from the other open threads. Any pointers appreciated.