How do I know if my game has a freeze problem?

Look for the game hanging and becoming unresponsive, distinct from crashing. The defining sign is the game hanging and becoming unresponsive, it stops responding to input and the screen doesn't update, but it hasn't crashed (the process is still running, just stuck). A sign is players reporting the game 'froze,' 'stopped responding,' 'hung,' or 'locked up' (distinct from 'crashed'), often noting they had to force-close it. And a sign is freezes at specific moments (loading, a transition, a particular action) where the game hangs. What distinguishes a freeze from a crash is that the game is technically still running but stuck (unresponsive), rather than terminating, so there's no crash or stack trace, you diagnose a freeze by what the game was doing when it stopped responding, not from a crash report. To find it, capture the context (what the game was doing, the moment, breadcrumbs) around the hang, and note which moments freeze (loading, etc.). If the game hangs and becomes unresponsive (not crashing), players report it froze or stopped responding, or it freezes at specific moments, you have a freeze problem. The key is the signature: unresponsive but still running (stuck, not terminated), which is what distinguishes a freeze from a crash and which means you diagnose it from the context of the hang (the moment, what the game was doing) rather than from a crash. Capturing what the game was doing when it froze (and which moments freeze) is how you find the cause, a blocked main thread (heavy work, often at loading), an infinite loop, or a deadlock, so you can fix it.

What causes a game to freeze?

The game getting stuck, unable to continue updating and rendering, which has a few common causes. The most frequent is the main thread being blocked: the main thread runs the game's update and render loop, so if a long operation, a heavy computation, a synchronous file or network load, an expensive calculation, runs on it, the game can't update or render until that operation finishes, and it appears frozen for the duration (this is why freezes often occur at loading, a synchronous load blocks the main thread). Worse are infinite loops and deadlocks: an infinite loop (a loop whose condition never becomes false) runs forever, and a deadlock (two or more things each waiting for the other to release something) waits forever, both of which hang the game permanently with no recovery. There can also be freezes from waiting on something external that never responds. What unites freezes is that the game is technically still running but stuck (unlike a crash where it terminates), so it's unresponsive without crashing. So a game freezes because it gets stuck, most commonly the main thread blocked by heavy work (a long synchronous operation, often at loading), an infinite loop (execution that never completes), or a deadlock (things waiting on each other forever). To find the cause, note which moments freeze (loading suggests a blocking load on the main thread; a freeze that never recovers suggests an infinite loop or deadlock) and capture what the game was doing when it froze (the context, breadcrumbs), since there's no crash, the context of the hang is what points at the cause. The fix targets the specific cause: keep heavy work off the main thread (do long operations asynchronously or in the background, so they don't block the update/render loop, this fixes the common loading-freeze case), guard against infinite loops and deadlocks (careful loop conditions and locking), and handle waiting on external things (timeouts). So freezes come from the game getting stuck (main thread blocked, infinite loop, deadlock, or waiting forever), and fixing them means addressing the specific stuck-state cause, most commonly moving heavy work off the main thread so it doesn't block, plus guarding against loops and deadlocks. Because freezes have no crash, finding them relies on the context of the hang (which moment, what the game was doing) rather than crash data.

Is a freeze different from a crash?

Yes, though both make the game unplayable, they're technically different and need different prevention. A crash is when the game terminates, an error, exception, or fatal condition causes the process to stop, often producing a stack trace you can capture. A freeze (or hang) is when the game doesn't terminate but becomes unresponsive, it's technically still running but stuck, unable to update or render, so it appears hung and the player can't interact with it (often needing a force-close). The causes differ: crashes come from errors and invalid operations (null references, exceptions, memory issues), while freezes come from the game getting stuck (the main thread blocked by heavy work, an infinite loop, a deadlock, waiting on something that never responds). They also surface differently in diagnosis: a crash typically gives you a stack trace pointing at where it failed (so you capture and diagnose it from the crash report), while a freeze doesn't crash, so you have to capture what the game was doing when it stopped responding to find the cause (the context of the hang, not a crash report). From the player's perspective both are bad (an unresponsive frozen game is as frustrating as a crashed one, both end the session), but preventing freezes specifically means addressing the stuck-state causes (keeping the main thread free of blocking work, avoiding infinite loops and deadlocks) rather than the error-handling that prevents crashes. So a freeze is different from a crash: a freeze is the game stuck/unresponsive but still running (caused by getting stuck, main thread blocked, loop, deadlock), while a crash is the game terminating (caused by errors). They need different diagnosis (freeze: context of the hang; crash: stack trace) and different prevention (freeze: keep main thread free, avoid loops/deadlocks; crash: error handling, defensive coding). Recognizing the distinction matters: if players report the game 'froze' or 'stopped responding' (not 'crashed'), you have a freeze, which you diagnose from the context of the hang (since there's no crash report) and fix by addressing the stuck-state cause (most commonly moving heavy work off the main thread). Capturing both crashes (with stack traces) and freeze context (what the game was doing when it hung) from the field lets you see and fix each, but they're distinct problems requiring distinct approaches, so it helps to think of a freeze as a separate issue from a crash even though both make the game unplayable.

Signs Your Game Has a Freeze Problem

Quick answer: Watch for the game hanging and becoming unresponsive (not a crash), players reporting it 'froze' or 'stopped responding,' freezes at specific moments like loading, and the need to force-close. A freeze hangs the game while it's still running.

A freeze, the game hanging and becoming unresponsive while technically still running, frustrates players as much as a crash. Here are the signs your game has a freeze problem.

The Game Hanging and Becoming Unresponsive

The defining sign is the game hanging and becoming unresponsive, it stops responding to input, the screen doesn't update, but it hasn't crashed (the process is still running, just stuck). Reports of the game 'freezing,' 'hanging,' or 'not responding' (distinct from crashing) point at a freeze problem.

Bugnet captures context, so you can understand what the game was doing when it froze. The game hanging and becoming unresponsive is the defining sign of a freeze, and since a freeze isn't a crash (no termination, no stack trace), you diagnose it by capturing what the game was doing when it stopped responding, the context around the hang points at the cause (a blocked main thread, a loop, a deadlock).

Players Reporting It 'Froze' or 'Stopped Responding'

A sign is players reporting the game 'froze,' 'stopped responding,' 'hung,' or 'locked up,' distinct from 'crashed.' Players describe a freeze specifically (the game stuck, not closing), often noting they had to force-close it. This distinctive description points at a freeze rather than a crash.

Bugnet captures context, so freeze situations are identifiable from the surrounding data. Players reporting it froze or stopped responding is a distinctive sign of a freeze (the game stuck, not crashed), and since there's no crash to capture, locating it relies on what the game was doing when it froze (the context, the moment), which capturing context around the hang helps reveal.

Freezes at Specific Moments Like Loading

A sign is freezes at specific moments, loading, a transition, a particular action, where the game hangs. Freezes often occur when something blocks the main thread (a long synchronous operation like loading) or hits a loop/deadlock. So freezes clustering at specific moments point at what's blocking, e.g. heavy work on the main thread at loading.

Bugnet captures context with breadcrumbs, so freezes at specific moments are identifiable. Freezes at specific moments like loading are a sign of what's causing the hang (e.g. heavy work blocking the main thread during loading), and seeing which moments freeze (via context and breadcrumbs) points at the cause, a blocking operation at that moment, a loop, or a deadlock, so you can target the fix.

Watch for the game hanging and becoming unresponsive (not a crash), players reporting it 'froze' or 'stopped responding,' freezes at specific moments like loading, and the need to force-close. A freeze hangs the game while it's still running.