1) Isolate the network
- Switch networks (Wi‑Fi ↔ 4G/5G).
- Disable VPN/proxy (or test with/without).
2) Isolate browser/app
- Private window.
- Update the app.
- Clear cache/cookies.
3) Account
- Confirm credentials.
- Complete verification (SMS/email) if requested.
4) Payments
- Check bank/card limits.
- Try another method.
- If it’s an outage, retry later.
5) If it persists
- Note the time and error message and contact in-app support.