Quick answer: Move slow work (loading, networking, heavy computation) off the main thread, keep per-frame work bounded, and never block the UI thread on I/O.
An ANR means your main thread stopped responding long enough for Android to flag it. The fix is keeping that thread free of blocking work. Here is how.
How to fix it
1. Move slow work off the main thread
Asset loading, decompression, and big computations belong on background threads or jobs. Anything that takes more than a frame on the main thread risks an ANR.
2. Never block on I/O
Synchronous file or network calls on the main thread are a classic ANR cause. Use async loading and networking so the thread keeps servicing the UI and input.
3. Bound per-frame work
Spawning hundreds of objects or running a huge loop in one frame can freeze the thread long enough to trip the watchdog. Spread heavy work across frames.
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 mobile 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.
Most of the time the fix is small. Seeing the failure clearly is the part that actually costs you.