What causes a boss gate unlocking before the floor is cleared?

The gate checks an enemy count that is decremented incorrectly or initialized wrong, so it reaches zero (and opens) while enemies remain.

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 Boss Gate Opening Before the Floor Is Cleared

Quick answer: Track remaining enemies with a count that increments on spawn and decrements only on confirmed death, and open the gate strictly when that count hits zero.

A boss gate that opens with enemies still alive means your live-enemy count is wrong. Incrementing on spawn and decrementing on death, with no double-counts, fixes the gate logic.

How to fix it

1. Count on spawn and death only

Increment the remaining-enemy counter when an enemy spawns and decrement it in the death handler, ensuring each enemy is counted exactly once each way.

2. Guard against double decrement

Set a flag when an enemy starts dying so its death handler cannot decrement twice from overlapping damage events, which would zero the count early.

3. Recount as a safety net

If the count hits zero, verify by querying the actual live enemies in the room before opening the gate, so a counting bug cannot trigger an early open.

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.

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