What causes an Unreal montage running at the wrong speed in slow motion?

The montage was played at a fixed play rate that does not account for the actor's custom time dilation, so it advances out of sync with slowed gameplay.

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 an Unreal Montage Desyncing With Gameplay Because Play Rate Ignores Time Dilation

Quick answer: Play the montage with a play rate and rely on the mesh's tick respecting time dilation, or explicitly multiply the play rate by the desired dilation when you want it independent.

When you trigger slow-motion, a montage either ignores it or double-applies it depending on how it was started. Here is how to keep the montage in step with gameplay time.

How to fix it

1. Let the mesh tick honor dilation

By default the skeletal mesh advances with the actor's tick, which already scales by Custom Time Dilation. Avoid manually re-scaling play rate by the same factor or you slow it twice.

2. Drive intentional independence explicitly

If a montage must run at real time during slow-mo, set the mesh component's bIgnoreCustomTimeDilation-style behavior or compute a compensating play rate so it stays at full speed.

3. Set play rate at play time

Pass the desired rate to Montage_Play(Montage, Rate) and adjust later with Montage_SetPlayRate, rather than changing global dilation to speed one montage.

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.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.