What causes tool durability never decreasing?

Durability is decremented on a copy of the item struct rather than the inventory's stored instance, or the item is stackable so per-item durability cannot be tracked.

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 Tool Durability Never Decreasing No Matter How Much You Use It

Quick answer: Store durability on a unique non-stackable instance and write the decrement back to the inventory slot that actually holds it.

A pickaxe never wears down because the damage is applied to a value copy that is thrown away. Items meant to track durability must be unique instances, not entries in a stack.

How to fix it

1. Make damageable items non-stackable

Tools with durability must each be their own instance with a max stack of one. You cannot track per-item wear on a merged stack of identical entries.

2. Write back to the slot

If your item is a value type or struct, mutate the copy then assign it back into the inventory slot. Decrementing a local copy discards the change immediately.

3. Break at zero

When durability hits zero, remove or convert the item to a broken state in the same write so it cannot keep being used at full effectiveness.

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.

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