Failed downloads are usually one of three things: a network hiccup, full storage or a stuck Play Store queue. Check them in that order.
- 1Toggle Wi-Fi off/on; try mobile data, some routers silently block Play downloads.
- 2Check free space: you need at least the app size plus ~1 GB headroom.
- 3Cancel stuck downloads in Play Store → profile → Manage apps → pending queue.
- 4Clear Play Store cache and data (Settings → Apps → Google Play Store → Storage).
- 5Check Download Manager is enabled: Settings → Apps → show system → Download Manager.
- 6Re-add your Google account if downloads never start.
Tip: On metered connections, Play defaults to 'Ask every time' or Wi-Fi-only, check Play Store → Settings → Network preferences.