Were Logprobs disabled for Gemini 3/3.1 in Vertex API?

Gemini API
1

As of today, I run into the following error for gemini-3-pro-preview and gemini-3.1-pro-preview when using the Vertex API. Prior to today, this functionality was working without issue.

- {

  "error": {

    "code": 400,

    "message": "Unable to submit request because Logprobs is not supported for this model. Learn more: 
",

    "status": "INVALID_ARGUMENT"

  }

}

Note that I query Gemini via the following:

vertexai.init(project=project, location="global")

model = GenerativeModel(model_name, system_instruction=_CLASSIFIER_SYSTEM_INSTRUCTION,)
config = GenerationConfig(temperature=0.0,response_logprobs=True,logprobs=5)
response = model.generate_content(prompt, generation_config=config)
1 Like
2

Definitely broken. Stopped working for me today. I hope they bring it back ASAP.