Quick answer: Respect the maximum stack size when merging, handle overflow into a new stack, and keep total counts correct across splits and merges.

Material stacking bugs are merge and split miscounts. Here is how to fix them.

How to fix it

1. Respect the max stack size

When merging stacks, fill up to the maximum stack size and put the remainder in another stack. Ignoring the cap creates over-cap stacks or loses items that should have overflowed.

2. Handle overflow correctly

When a merge exceeds the max, the excess must go into a new or existing partial stack, not vanish. Dropping the overflow loses materials; handle it so the total is preserved.

3. Keep totals correct

Across every split and merge, the total material count must stay constant. Verify that combining and splitting stacks conserves the total, since off-by-one or overflow bugs here silently gain or lose materials.

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.

Most of the time the fix is small. Seeing the failure clearly is the part that actually costs you.