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 Clicks When Crossfading Music Tracks in an Unreal Sound Cue

Q: What causes clicks when crossfading music tracks in an Unreal Sound Cue?

The crossfade is too abrupt or the two tracks aren't at matching phase, so the sudden gain change at the swap produces a click.

Quick answer: Use a Crossfade By Param node with overlapping fade in/out ranges, give the transition enough time, and ensure both tracks start at zero crossings.

Switching combat music in a Sound Cue produces a tick at the handover. A hard or mistimed crossfade leaves a discontinuity exactly where the tracks swap.

How to fix it

1. Use Crossfade By Param

Drive the swap with a Crossfade By Param node and set overlapping FadeInDistance/FadeOutDistance so one track ramps up while the other ramps down.

2. Lengthen the fade

A crossfade under ~100 ms can click. Give the parameter interpolation enough time so neither track jumps in gain.

3. Align track starts

Author both stems to begin and end at zero crossings so the moment of overlap doesn't introduce a step in the waveform.

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 Unreal Engine 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 bug you can't reproduce isn't gone — it's just invisible until you capture it from the player's device.