Quick answer: Compute the preview through the same stat pipeline as actually equipping, including all modifiers, so the preview exactly matches the real outcome.
Wrong stat previews are duplicated, divergent calculations. Using one pipeline fixes it. Here is how.
How to fix it
1. Use the real stat pipeline
Compute the preview by simulating the actual equip through the same stat calculation the game uses when equipping, rather than a separate simplified preview formula that diverges from reality.
2. Include all modifiers
Account for set bonuses, conditional modifiers, and stacking rules in the preview, since these affect the real result. A preview that ignores them shows a change that does not match what the player gets.
3. Show the true delta
Present the difference between the current and previewed total stats, computed consistently, so the player sees exactly what will change. A delta from inconsistent calculations misleads and erodes trust in the UI.
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.
Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.