---
title: "Google Login Error 400 'malformed request' in TAC — sign-in fails even after format"
canonical_url: https://emudesk.com/issues/google-login-error-400-malformed-tac
content_locale: en
source_locale: en
entity_type: issue
index_status: index
published_at: 2026-08-31T18:22:23.000Z
updated_at: 2026-09-01T00:45:02.086Z
freshness_status: fresh
---

# Google Login Error 400 'malformed request' in TAC — sign-in fails even after format

When trying to sign into Google services inside TAC (Play Store, YouTube, anything that requires Google OAuth), the login flow shows a Google error page:


400. That's an error.
The server cannot process the request because it is malformed. It should not be retried. That's all we know.


This blocks Play Store sign-in, account-bound CODM features, cross-device save sync, and friend lists. Reported framing:

  "buenas estoy teniendo este problema.. alguien mas le paso? ya borre cache, desintale gameloop lo volvi a instalar y hasta formatie la computadora pero me sigue apareciendo igual" — re22 (formatted Windows install, problem persists)
  The exact 400 dialog appears regardless of which Google account you try.
  Reinstall + cache clear + Windows format — none resolve the error.


Root cause: Google's OAuth endpoint detects an emulated client signature mismatch — TAC's OAuth handshake sends device-fingerprint headers that don't match a real Android device. Google rejects with 400 instead of a more helpful "device not supported" because the request body fails their schema validation entirely.