How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Non-Reproducible Unity Builds Caused by Asset Import Order

Q: What causes non-reproducible Unity builds caused by asset import order?

Differences in the Library cache, asset import order, or platform import state mean two machines import the same assets slightly differently, producing builds that are not bit-identical.

Quick answer: Use Asset Pipeline V2 with a clean Library on CI, pin importer versions, switch platform before building, and avoid GUID-dependent ordering so builds are deterministic across machines.

Your CI build and a local build differ even though the commit is identical. Asset import is sensitive to cache state and order, which can introduce non-determinism between machines.

How to fix it

1. Start from a clean import

On CI, build from a clean checkout so the Library is regenerated deterministically with Asset Pipeline V2, rather than reusing a cache that imported assets in a different order.

2. Switch platform first

Run a platform switch before the build so all assets are imported for the target platform once. Building right after a switch can mix re-imported and stale platform variants.

3. Remove order-dependence

Avoid logic that depends on asset import order or GUID iteration order in build scripts. Sort explicitly so the output does not change with the pipeline's traversal order.

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 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.

The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.