What causes a GameMaker tile layer at the wrong depth?

Layer depth, not creation order, decides draw order, and the tile layer's depth value places it above or below instance layers differently than you intended.

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 GameMaker Tile Layer Rendering Behind or In Front of Instances Wrongly

Quick answer: Reorder layers in the Room Editor so the tile layer sits between the right instance layers, or set layer depths explicitly with layer_depth so tiles render where you want.

Your foreground tiles vanish behind characters, or background tiles cover the player. The tile layer's depth relative to instance layers is wrong.

How to fix it

1. Reorder layers in the room editor

Drag the tile layer above or below the instance layers in the Layers panel. Higher in the list draws on top; depth is taken from layer order, not object creation.

2. Set depth explicitly in code

Use layer_depth(layer_get_id("Tiles_Fg"), -100) to force a tile layer in front, since lower depth draws later (on top).

3. Keep separate fore/back tile layers

Use distinct tile layers for foreground and background and place instance layers between them, so characters can walk in front of one and behind the other.

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.

The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.