[BUG] Antigravity 2.17.0 – Verification loop / 403 VALIDATION_REQUIRED after successful authentication on Windows

Google Antigravity
1

Environment

  • OS: Windows
  • Antigravity version: 2.17.0
  • Language server version: 2.5.5
  • Issue reproduced with two different Google accounts.
  • Tested with two different US VPN egress IPs / ASNs.
  • IPv6 is not available, so there is no IPv6 leak.

Problem
Antigravity repeatedly shows:

Verification required

and asks me to complete Google account verification.

The mobile verification flow succeeds and shows:

You're now verified. Return to your other device to continue.

However, on the PC the verification flow ends with:

We couldn't verify your info

and Antigravity continues to return Verification Required.

Important diagnostic result
After clearing stale authentication state, resetting onboarding, and signing in again, the Antigravity language server reports:

Auth succeeded, refreshing features and managers

so authentication itself is succeeding.

The backend then returns:

403 PERMISSION_DENIED

Verify your account to continue.

reason: VALIDATION_REQUIRED

from cloudcode-pa.googleapis.com.

The relevant loadCodeAssist trace is:

0x73828121e***

Additional diagnostic behavior
Before the new authentication state is established, the language server reports:

state syncing error: key not found

for the OAuth token / loadCodeAssist state.

After authentication succeeds, the issue changes to the backend validation error above, which suggests the local OAuth problem is no longer the blocker.

Troubleshooting already completed

  • Removed stale gemini:antigravity Windows Credential.
  • Removed stale antigravityUnifiedStateSync.oauthToken from state.vscdb.
  • Reset Antigravity Session Storage.
  • Used Antigravity IDE: Reset Onboarding.
  • Signed in again from a clean authentication state.
  • Confirmed Google authentication succeeds.
  • Tested two separate Google accounts.
  • Tested two different US IPs:
    • one via M247
    • one via tzulo
  • Confirmed Antigravity language_server.exe routes through the VPN.
  • Confirmed no IPv6 default route / IPv6 leak.
  • Account age/birthday is valid.
  • No unresolved Google security alert is visible.

Expected behavior
After successful Google verification, Antigravity should persist the verified state and allow Agent / Gemini Code Assist requests.

Actual behavior
Verification succeeds on the mobile device but the desktop flow fails, while the backend continues returning:

403 PERMISSION_DENIED / VALIDATION_REQUIRED

Request
Could the Antigravity / Gemini Code Assist team check the backend validation state for this account/session and the trace above?

This appears to be a validation-state synchronization issue rather than a local OAuth or network failure.

I can provide the full Antigravity IDE diagnostics file if needed.

2

i have met same problem

3

Hi @Eanibc_Ejnbc, welcome to the forum!

Could you please upgrade to the latest version of Antigravity (v2.18.1)? Once you have updated, please let me know if the issue is resolved or if it still persists!