Fix “Gemini 3 Pro is no longer available” in Antigravity

If you are a developer using Google’s latest AI-first IDE, you might have recently hit a frustrating roadblock. Right in the middle of a coding sprint, your agent suddenly stops working, and you see this exact error message: “Gemini 3 Pro is no longer available. Please switch to Gemini 3.1 Pro in the latest version of Antigravity.” This error has been flooding developer forums and Reddit communities recently. It completely halts your workflow, especially when the Antigravity application insists that “there are no updates available” when you try to fix it.

Do not panic! You are not alone, and your project files are perfectly safe. In this comprehensive guide, we will show you exactly how to fix “Gemini 3 Pro is no longer available in Antigravity.” We will walk you through step-by-step solutions, explain why this happened, and explore the exciting new features waiting for you in Gemini 3.1 Pro.

Let’s get your autonomous AI agents back online!

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Understanding the Error: Why Are You Seeing This Message?

Before we dive into the technical fixes, it helps to understand what is happening behind the scenes. Google Antigravity is a revolutionary “agent-first” development platform. Unlike traditional code-completion tools, it uses autonomous agents to plan, write, and test code for you.

To power these agents, Antigravity relies heavily on massive Large Language Models (LLMs). Recently, Google made a major backend shift.

The Shift from Gemini 3 Pro to Gemini 3.1 Pro

In mid-February 2026, Google officially released Gemini 3.1 Pro. This new model boasts significantly advanced reasoning capabilities, better context retention, and improved multi-step problem-solving skills.

Because Gemini 3.1 Pro is designed to completely replace its predecessor, Google deprecated the older Gemini 3 Pro model. When the server-side switch happened, any older version of the Antigravity IDE trying to ping the Gemini 3 Pro API was instantly blocked, triggering the error message you are seeing.

Why the Auto-Updater Fails

You might be wondering, “Why doesn’t the app just update itself?”

This is where the bug lies. Many users on Antigravity versions prior to v1.18.3 experienced a glitch where the built-in auto-updater failed to recognize the new release. When users clicked “Check for Updates,” the IDE falsely reported that no updates were available.

Because the old app cannot access the deprecated model, and it cannot see the new model, it gets stuck in a loop. You have to manually force the platform to update.

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Step-by-Step Guide to Fix Gemini 3 Pro is no longer available in Antigravity

The good news is that the solution is incredibly simple. You do not need to delete your projects, and you will not lose your customized settings or extensions. Here are the three best methods to resolve this issue.

Method 1: The Direct Overwrite (Best for Windows & Mac)

This is the most reliable and widely successful method reported by the developer community. It involves manually downloading the newest installer and running it directly over your existing installation.

Follow these exact steps:

1. Close the IDE completely: Ensure Antigravity is not running in the background. Force quit the application if necessary.
2. Visit the official website: Open your web browser and go to antigravity.google.
3. Download the latest installer: Click the primary download button to grab the newest executable file (ensure it is version 1.18.3 or higher).
4. Run the installer directly: Do not uninstall your current version of Antigravity. Simply run the new installer you just downloaded.
5. Follow the prompts: Let the setup wizard complete the installation process.
6. Launch the application: Open Antigravity. The underlying architecture is now updated, but your workspace, themes, and agent histories remain perfectly intact.

Pro Tip: Overwriting the application preserves your “Artifacts” panel, so any previous implementation plans or browser recordings generated by your agents will still be there.

Method 2: The Command Line Fix (Winget & APT)

If you are a power user who prefers keeping your hands on the keyboard, you can bypass the website entirely and use package managers to force the update.

For Windows Users (using Winget):

Open your Command Prompt (CMD) or PowerShell as an administrator. Type the following command and hit Enter:

winget upgrade Google.Antigravity

Wait for the package manager to fetch the latest version from the repository and install it.

For Linux Users (using APT):

Open your terminal and run the standard update and upgrade commands:

sudo apt update

sudo apt --only-upgrade install antigravity

Once the command finishes executing, relaunch your IDE. The new model definitions will now be loaded.

Method 3: The Hard Restart (When 3.1 Pro is Hidden)

Sometimes, users successfully update the app but face a secondary glitch: the new model does not appear in the dropdown menu. You might update the app, but still see the “switch to Gemini 3.1 Pro” message without any way to actually select it.

Here is how to fix the hidden model issue:

1. Log out of your account: Inside Antigravity, click on your profile icon and sign out of your Google account.
2. Force quit the app: Completely close the application. On Mac, use Cmd + Q. On Windows, ensure it is closed via the Task Manager.
3. Relaunch and log in: Open the app again and sign back into your Google account.
4. Check the Agent Manager: Navigate to the Agent Manager panel. Click the model dropdown menu. Gemini 3.1 Pro should now be prominently displayed and ready for selection.

(Internal Linking Suggestion: You may also read our complete guide on Setting up Agent Workspaces in Google Antigravity for more optimization tips.)

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What to Do After Fixing the Error

Once you have bypassed the error, there are a few housekeeping items you need to take care of to ensure a smooth transition.

1. Selecting the New Model

By default, your older workspaces might still be trying to point to the deprecated model. Open your active workspace, navigate to the Agent Side Panel, and manually ensure “Gemini 3.1 Pro” is selected from the model list.

2. Verifying Your Workspaces

Check your Artifacts panel. Ensure that your Task Lists and Implementation Plans from previous sessions are still readable. If an agent was in the middle of a task when the error occurred, it is highly recommended to start a fresh chat or prompt to avoid context confusion.

3. Monitoring Quota Usage

Be aware that Gemini 3.1 Pro is a more powerful model. Some users have reported that it consumes tokens slightly faster for complex reasoning tasks. Keep an eye on your usage limits if you are on the free tier.

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Meet Gemini 3.1 Pro: What’s New in Google Antigravity?

Now that you have successfully fixed the error, let’s look at the bright side. You are now equipped with Google’s most advanced AI model for coding. The forced upgrade is actually a massive blessing for your productivity.

Advanced Reasoning for Complex Workflows

Gemini 3.1 Pro marks a significant leap in fundamental reasoning. While the older version was great at writing scripts, 3.1 Pro is built for scenarios where basic responses fall short.

It can navigate intricate, long-horizon tasks across entire codebases. For example, if you ask it to “refactor the authentication module,” it doesn’t just rewrite code; it assesses risks, creates a local-first sync strategy, and maintains perfect context across dozens of files.

Better Autonomous Agent Features

Antigravity operates on four key tenets: Trust, Autonomy, Feedback, and Self-improvement. Gemini 3.1 Pro enhances all of these.

The agents are now less prone to “hallucinations” and are much better at verifying their own work. They will autonomously spin up local servers, test their UI changes using the built-in browser, and provide you with a video recording of the successful test.

Comparison Table: Gemini 3 Pro vs. Gemini 3.1 Pro

Here is a quick breakdown of why the new model is vastly superior:

Feature	Gemini 3 Pro (Deprecated)	Gemini 3.1 Pro (New)
Agentic Autonomy	Good for single-file scripts	Excellent for multi-file architecture
Complex Reasoning	Often required human intervention	High success rate on complex logic
Bug Fixing	Required exact terminal errors	Autonomously finds and fixes UI bugs
Context Retention	Lost context in long workflows	Maintains context across whole codebase
Status in Antigravity	Deprecated / Blocked	Active and Native Integration

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Troubleshooting Common Post-Update Issues

Even after fixing the main error, transitioning to a new IDE version can come with minor hiccups. Here are the most common post-update issues and how to resolve them.

Issue 1: High Token Usage or Quota Drain

Because Gemini 3.1 Pro “thinks deeper” before acting, it naturally consumes more tokens. If your quota is vanishing too quickly:

• Fix: Be highly specific with your prompts. Instead of saying “Fix my app,” say “Analyze the login component and fix the state management bug.” Narrowing the scope reduces the files the agent needs to read.

Issue 2: Endless “Generating” Loops

Some users report the agent getting stuck on “Working” or “Generating” after the update.

• Fix: This is often a local caching issue. Close your current workspace, clear the agent history for that specific task, and prompt it again. If it persists, restarting the Antigravity application usually clears the memory leak.

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Best Practices for Using Gemini 3.1 Pro in Antigravity

To get the absolute most out of this powerful new setup, you need to adapt your workflow. You are no longer just writing code; you are managing an intelligent team of digital developers.

Write Goal-Based Prompts

Traditional AI tools required you to ask for specific code snippets. With Gemini 3.1 Pro, you need to assign goals.

• Bad Prompt: “Write a Python function to connect to a PostgreSQL database.”
• Good Prompt: “Build a secure database connection module for PostgreSQL. Include error handling, retry logic, and write a test suite to verify the connection.”

Leverage the Agent Manager

Do not wait for one task to finish before starting another. Antigravity allows asynchronous task execution.

• Open the Agent Manager view.
• Spawn one agent to update your dependencies.
• Spawn a second agent to write unit tests for your billing API.
• Let them run in parallel while you review their generated Implementation Plans.

Review Artifacts Regularly

Always review the “Task Lists” and “Implementation Plans” generated by the AI before you let it execute terminal commands. This ensures the AI’s logic aligns with your project’s architecture, saving you from having to revert massive unwanted changes later.

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Frequently Asked Questions (FAQs)

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Conclusion & Next Steps

Hitting the “Gemini 3 Pro is no longer available” error can be a jarring interruption to your development flow. However, as we have explored, the fix is as simple as grabbing the latest installer from the official website and running an in-place upgrade.

By forcing this update, you are not just fixing a bug; you are unlocking the incredible power of Gemini 3.1 Pro. With its advanced reasoning, superior multi-file context retention, and improved agent autonomy, your coding workflow is about to get a massive speed boost.

Actionable Next Steps:

1. Head over to antigravity.google right now and download the latest version.
2. Run the installer without uninstalling your current setup.
3. Restart your IDE, select Gemini 3.1 Pro, and throw your hardest coding challenge at it!

(External Reference: Want to learn more about the specific benchmarking of the new model? Check out the official Gemini 3.1 Pro Model Card by Google DeepMind.)