Restart the phone, free up storage (keep 10%+ free), update all apps and Android, remove recently added widgets and live wallpapers, clear the cache of Google and your launcher app, and boot into Safe Mode to see if a third-party app is responsible.

What's going on

System UI depends on the launcher, Google app components and widgets. A bad widget, a launcher bug or low memory can stall it. Safe Mode disables third-party apps, so it quickly shows whether one is to blame.

How it shows up

  • Pop-up: “System UI isn't responding” with Close app / Wait.
  • Frozen status bar or notification shade.
  • Black screen after unlocking.

Common causes

  • Low storage or RAM.
  • Buggy app or system update.
  • Third-party launcher, widgets or live wallpaper.
  • Corrupted cache.

How to fix it, step by step

  1. RestartHold Power (or Power + Volume Up) and choose Restart.
  2. Free storageSettings → Storage; remove large files and unused apps.
  3. Update everythingPlay Store updates and Settings → System → Software update.
  4. Remove widgets and live wallpaperEspecially ones added before the problem began.
  5. Clear cachesSettings → Apps → (show system apps) → Google, your launcher → Storage → Clear cache.
  6. Safe Mode testHold Power, then press and hold Power off → Safe mode. If the issue stops, uninstall recently installed apps.
  7. Factory reset as last resortBack up first: Settings → System → Reset options.
How to tell it worked: No more System UI pop-ups for several days.

Keeping it from coming back

Keep 10%+ storage free and limit third-party launchers and widgets.