Fix 'Google Play Services Keeps Stopping'

Google Play services is the invisible layer most apps depend on. When it crash-loops, notifications, maps and sign-ins break everywhere. The fix ladder below resolves nearly all cases.

1. 1Reboot first, a surprising number of crash loops end there.
2. 2Settings → Apps → Google Play services → Storage → Clear cache.
3. 3Same screen → 'Manage space' / Clear data (your files are untouched).
4. 4Update Play services: play.google.com/store/apps/details?id=com.google.android.gms in the browser → Update.
5. 5Update Android WebView and Chrome in the Play Store, old WebViews famously crash services.
6. 6Check date & time are automatic.
7. 7Remove and re-add the Google account if crashes persist.