Persistent 404 "Publisher Model not found" error for gemini-1.5-flash in Vertex AI

Google Cloud Build with AI Generative AI & Foundational Models
1

Hello Google Cloud Community,

I am consistently encountering a “404 Publisher Model not found” error when trying to access gemini-1.5-flash (and gemini-1.0-pro) models via the Vertex AI Python SDK. I have a paid Google Cloud billing account, but my support plan is Basic, so I’m seeking help here.

Project ID: (PII Removed by Staff)
Region: us-central1 (also tried asia-northeast1)
Model IDs attempted: gemini-1.5-flash, gemini-1.0-pro (both give 404)

Steps I have already taken:

  1. Billing: My billing account is active and on a paid plan (not a free trial).
  2. Authentication: A service account (detail-page-generator-sa) has been created for (PII Removed by Staff) with the “Vertex
    AI User” role. The service account key is correctly set via GOOGLE_APPLICATION_CREDENTIALS environment variable,
    and vertexai.init() is successful.
  3. API Enablement: Both “Vertex AI API” and “Generative Language API” are confirmed to be enabled in the project.
  4. Client Library: google-cloud-aiplatform library is updated to the latest version.
  5. Tested code (example snippet):
1     import os
2     from dotenv import load_dotenv
3     import vertexai
4     from vertexai.generative_models import GenerativeModel
5
6     load_dotenv()
7     project_id = os.getenv("GOOGLE_CLOUD_PROJECT")
8     location = os.getenv("GOOGLE_CLOUD_LOCATION") # Currently us-central1
9

10 vertexai.init(project=project_id, location=location)
11 model = GenerativeModel(“gemini-1.5-flash”) # Also tried “gemini-1.0-pro”
12 response = model.generate_content(“Hello”)
13 print(response.text)
Error received:
404 Publisher Model projects/(PII Removed by Staff)/locations/us central1/publishers/google/models/gemini-1.5-flash was not
found or your project does not have access to it.

My question:
Could anyone provide insights into why this error persists despite all configurations appearing correct? Is there a specific IAM permission, project setting, or API that I might be missing for gemini-1.5-flash access? Or is there a different model ID I should be using for image processing/translation features similar to “Gemini 2.5 Flash Image”?

2

Hi @석봉_윤 ,

Thank you for the question.

All Gemini 1.5 (and previous) models are no longer supported on Vertex AI, as of late 2025. We recommends using or migrating to the newer Gemini 2.x or 3.x model families.

You can find more info here: Migrate to the latest Gemini models  |  Generative AI on Vertex AI  |  Google Cloud Documentation

Best