What causes a Unity NavMesh not baking?

The geometry is not marked Navigation Static, the agent size does not fit the space, or the area is marked non-walkable, so the bake produces no walkable mesh.

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 Unity NavMesh That Won't Bake

Quick answer: Mark floor geometry as Navigation Static, set an agent radius and height that fit, confirm areas are walkable, and bake from the Navigation window.

A NavMesh that bakes empty usually has unmarked geometry or a too-large agent. Here is how to get a usable bake.

How to fix it

1. Mark geometry Navigation Static

Only objects flagged Navigation Static are included in the bake. If the floor is not marked, nothing is walkable. Set the static flags on the surfaces you want navigable.

2. Fit the agent settings

An agent radius or height larger than the available space excludes it from the navmesh. Set the agent dimensions to match your character so the bake includes the spaces it should walk.

3. Check walkable areas and bake

Confirm surfaces are not marked Not Walkable and slopes are within the max angle, then bake from the Navigation window. Verify the blue mesh covers where agents should go.

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 Unity 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 bug you can't reproduce isn't gone — it's just invisible until you capture it from the player's device.