What causes a Unity layout group not refreshing after a data change?

Layout groups recompute on Unity's deferred layout pass, so reading or relying on child positions the same frame you add items shows stale, overlapping placement.

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 a Unity Layout Group Not Refreshing After Adding Items

Quick answer: Force an immediate rebuild with LayoutRebuilder after modifying children, or mark the layout dirty and wait a frame before depending on the new positions.

Newly instantiated list items can stack on top of each other because the layout group has not run its pass yet. Forcing an immediate layout rebuild after the change places everything correctly the same frame.

How to fix it

1. Force an immediate rebuild

After adding or removing children, call LayoutRebuilder.ForceRebuildLayoutImmediate(rect) on the layout root so positions and sizes update right away instead of next frame.

2. Mark the layout dirty

If you do not need positions this frame, call LayoutRebuilder.MarkLayoutForRebuild(rect) and let Unity recompute on its normal pass, which is cheaper than forcing it.

3. Avoid reading sizes too early

Do not read rect.sizeDelta or child positions in the same call that created them; wait for the rebuild so you act on the final layout, not the pre-layout values.

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 Unity 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.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.