How to Fix Tower Defense Enemies Not Rerouting When a Tower Is Sold in Unity

If selling a tower should open a shortcut but enemies keep taking the long way, their paths are stale. Recomputing on layout change fixes it. Here is how.

How to fix it

1. Recompute on layout change

When a tower is built, sold, or destroyed, regenerate the path or flow field from the goal across the whole grid in one pass.

2. Have enemies resample

Active enemies should read their direction from the shared flow field each step (or re-run their path from the current cell), so they immediately follow the updated route.

3. Throttle recomputes

Batch multiple layout changes in the same frame into a single recompute, and use a flow field so one computation serves all enemies cheaply.

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.