What causes a GameMaker hitbox that keeps hitting after the swing animation ends?

The hitbox instance is created at the start of the attack but never destroyed, so it stays in the room dealing damage long after the active frames of the swing are over.

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 Hitbox Lingering After the Swing Ends in GameMaker

Quick answer: Destroy or deactivate the hitbox instance when the active frames end, ideally on the specific animation frame, rather than letting it persist.

If enemies take damage from a sword that has already returned to idle, the hitbox object outlived its swing. Destroying it when the active window closes fixes the phantom hits. Here is how.

How to stop it

1. Destroy the hitbox at the end of the window

In the attacker's animation, when image_index passes the last active frame, call instance_destroy(hitbox) or set its active flag off so it stops colliding.

2. Bind lifetime to active frames

Create the hitbox only on the contact frames and remove it immediately after, instead of spawning it in the Create event and forgetting it.

3. Use Animation End as a safety net

In the Animation End event of the attack, destroy any leftover hitbox so an interrupted or looped animation never leaves one alive.

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 GameMaker 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.