How to Fix Mod Hot-Reload Leaving Stale Objects in the Scene

You hot-reload a mod's files to iterate quickly, but every reload leaves the old version's entities, event subscriptions, and timers running alongside the new ones. The cause is reloading without unwinding what the previous load created.

How to fix it

1. Track everything a mod creates

Record every object, event subscription, timer, and registered asset under the owning mod's id. Without ownership tracking you cannot tell what to remove on reload.

2. Run teardown before reload

When a file changes, first dispose the mod's tracked objects and unsubscribe its handlers, then load the new version. This prevents duplicates and stale callbacks firing into freed state.

3. Reset registries the mod wrote to

If the mod added recipes, items, or commands, clear its entries from those registries before re-registering, so you do not get duplicate or shadowed definitions.

4. Guard against partial reloads

If the new version fails to load, keep the old one disabled rather than half-applied. A failed reload should leave a known-clean state, not a mix of old and new objects.

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.