Remote session disconnects indefinitely with "Lost connection to the remote instance" banner

Google Antigravity
1

When opening or interacting with an Antigravity remote session (workspace: Vox / Cobrança De Relatório Comercial), the interface fails to maintain a connection to the backend environment. A persistent loading spinner appears in the center, accompanied by the error banner: “Lost connection to the remote instance. Please wait a minute or refresh the page.” Refreshing the page or waiting does not restore the connection. Detailed Steps to Reproduce • Navigate to the Antigravity remote web interface. • Open or switch to the project/workspace Vox / Cobrança De Relatório Comercial. • Attempt to load the session or enter a prompt using model Gemini 3.8 Flash Medium. • Observe that the center screen displays an infinite loading spinner, the bottom input shows continuous spinning activity indicators, and the error banner appears above the input box. • Relevant Environment Details & Visual Evidence • OS: macOS (fill in your version, e.g., macOS Sonoma 14.x / Sequoia 15.x) • Browser: (e.g., Google Chrome Version 128.x / Safari / Brave) • Model Selected: Gemini 3.8 Flash Medium • Workspace / Project: Vox / Cobrança De Relatório Comercial • Visual Evidence: (Attach your screenshot here: Screenshot 2026-09-22 at 8.38.40 PM.png)

Screenshot_2026-09-22_at_8.43.34_PM
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Screenshot_2026-09-22_at_8.38.40_PM
Screenshot_2026-09-22_at_8.38.40_PM2418×1496 136 KB

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Hi @Gabriel_Kemmer, Welcome to the Forum!

Thanks for the screenshots. The remote web page doesn’t run Antigravity itself. It connects to the Antigravity app on one of your computers. The “Lost connection” message means the browser can’t reach that computer anymore. Your project and the model aren’t the problem.

A few things to try:

  1. Check the computer. Make sure it’s on, awake and online. Antigravity should be open there and signed in with the same account. If it looks stuck, quit it (⌘Q) and reopen it.
  2. Stop it from sleeping. If it’s a Mac, closing the lid or letting it sleep cuts the connection. Keep it plugged in, then go to System Settings → Battery → Options and turn on “Prevent automatic sleeping…”.
  3. Try your MacBook Air. Your screenshot shows “Continue on: Macbook Air”, so that Mac is online. If the workspace is on it, just click it.
  4. Check your network. Turn off any VPN or proxy on both devices, or try a phone hotspot.
  5. Refresh the browser. Do a hard refresh (⌘ + Shift + R). If that doesn’t help, try an Incognito window with extensions off.

If it still won’t connect, send us your Antigravity version, browser version, and roughly when it happened, and we’ll dig in.