How to Fix a Unity Mobile Game Not Saving When Swiped Away From Recents

A tester plays, hits home, then clears the app from recents and finds their progress gone. The mistake is saving in OnApplicationQuit, which mobile platforms are free to skip when they kill a backgrounded process. Save earlier instead.

How to fix it

1. Save on pause, not quit

Persist state inside OnApplicationPause(bool pause) when pause is true. This callback reliably fires when the app moves to the background, before the OS may terminate it.

2. Keep the write fast and atomic

Backgrounding gives you only a short window, so write to a temp file and rename, and avoid serializing huge object graphs that could be cut off mid-write.

3. Test the real kill path

On Android use adb shell am kill or swipe from recents; on iOS background then force-quit. Verifying with the editor's stop button hides the bug because the editor does call quit.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.