Vertex AI

Google Cloud Build with AI Custom ML & MLOps
1

Title: Persistent “404 Publisher Model Not Found” Error in Vertex AI Despite Correct Configuration

Hello,

I am encountering a persistent 404 Publisher Model not found error when trying to access any Gemini model via the Vertex AI Python SDK, and I have exhausted all standard troubleshooting steps. I’m hoping someone can provide insight into what might be causing this account-specific issue.

The Goal:

I am trying to run a simple Python script using the langchain-google-vertexai library to invoke a Gemini model.

The Error:

The script consistently fails with the following error, regardless of which model I try (gemini-1.0-pro, gemini-1.5-pro-latest, gemini-1.5-flash-latest, gemini-1.0-pro-vision):

404 Publisher Model `projects/devcon-prod-env/locations/europe-west1/publishers/google/models/gemini-1.0-pro-vision` was not found or your project does not have access to it.

Troubleshooting Steps Already Taken

I have confirmed the following:

1. Project Configuration is Correct:

  • I created a brand new project (devcon-prod-env) to rule out issues with the old one.

  • The project is correctly set as my default in gcloud:

    $ gcloud config get-value project
devcon-prod-env

2. Billing is Active:

  • The project is linked to an active and verified billing account. The output of gcloud billing projects describe devcon-prod-env confirms this:

    billingAccountName: billingAccounts/01A9B1-DAEADF-718682
billingEnabled: true

3. Vertex AI API is Enabled:

  • The aiplatform.googleapis.com service is enabled for the project. The output of gcloud services list --enabled includes:

    NAME                         TITLE
aiplatform.googleapis.com    Vertex AI API

4. Authentication is Correct:

  • I have logged in and set the quota project for my Application Default Credentials correctly:

    $ gcloud auth application-default set-quota-project devcon-prod-env

5. Code is Correct:

  • I am using a minimal, reproducible script that explicitly sets the model and location.

Code to Reproduce the Error

Here are the exact files to reproduce the issue.

run_agent.py:

import sys
import logging
from langchain_google_vertexai import VertexAI
from langchain_core.prompts import ChatPromptTemplate

logging.basicConfig(level=logging.INFO)

MODEL_NAME = "gemini-1.0-pro-vision" 
LOCATION = "europe-west1"

def run_agent_task(task_prompt: str):
    logging.info(f"Initializing model '{MODEL_NAME}' in location: {LOCATION}...")
    try:
        model = VertexAI(model_name=MODEL_NAME, location=LOCATION)
        
        prompt_template = ChatPromptTemplate.from_messages([("user", task_prompt)])
        chain = prompt_template | model
        
        logging.info("Invoking agent...")
        response = chain.invoke({})
        print("--- AGENT RESPONSE ---")
        print(response.content)

    except Exception as e:
        logging.error(f"An error occurred: {e}")

if __name__ == "__main__":
    run_agent_task("Hello, world.")

My Question

Given that billing is enabled, the API is active, authentication is correct, and the code explicitly calls a known model in a supported region, what could be causing this persistent “404 Publisher Model Not Found” error? Is there a hidden permission or account-level setting that I might be missing?

Thank you for any help you can provide.

2

@AB9 The Gemini models you used gemini-1.0-pro, gemini-1.5-pro-latest, gemini-1.5-flash-latest, gemini-1.0-pro-vision are no longer available to new users/projects. Please see this page for the latest available models: https://cloud.google.com/vertex-ai/generative-ai/docs/models.

3

Hi Eric ,

i am curious to know , does it mean from time to time ,we need to change the code to upkept the model version to keep our production working fine. ?

Thanks
Elise

4

Hi Elise, yes, it’s a good practice to be prepared for model updates. Google manages the lifecycle of its models, and while they strive for stability, LLMs continue to evolve and new model versions and updates are released. I often keep track of the model versions and lifecycle here: Model versions and lifecycle  |  Generative AI on Vertex AI  |  Google Cloud