What causes Unreal net relevancy culling hiding needed actors?

An actor's NetCullDistanceSquared is too small or a custom IsNetRelevantFor excludes the player, so the server stops replicating it even though it should be visible.

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 Unreal Net Relevancy Culling Hiding Actors Players Should See

Quick answer: Raise NetCullDistanceSquared for actors that must be seen at range, mark always-relevant actors with bAlwaysRelevant, and review any IsNetRelevantFor override.

Unreal only replicates actors it deems relevant to each connection, primarily by distance. An aggressive net cull distance or a faulty relevancy override makes important actors vanish for clients past a threshold.

How to fix it

1. Increase the net cull distance

Set NetCullDistanceSquared to cover the range at which the actor must remain visible. Remember it is the squared distance, so a 10000-unit range is 10000*10000.

2. Mark critical actors always relevant

For bosses, objectives, or anything that must replicate everywhere, set bAlwaysRelevant = true so relevancy culling never drops them, accepting the bandwidth cost.

3. Audit IsNetRelevantFor overrides

If you override IsNetRelevantFor, verify it returns true for the players who should see the actor; a too-strict custom rule silently culls it regardless of distance.

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