How to Fix a WebGL Build That Fails Because Brotli Files Are Not Decompressed

A WebGL build loads from the editor's local server but fails on your host with a wasm or data parse error because the Brotli files arrive still compressed. Setting the encoding headers fixes it.

How to fix it

1. Send the right encoding headers

Configure the host to serve *.br with Content-Encoding: br and the underlying type (e.g. application/wasm for the wasm.br). Without this header the browser does not decompress the response.

2. Or enable decompression fallback

In Unity Player Settings, turn on Decompression Fallback so the loader includes a JS decompressor and works even when the server cannot set the headers. This trades a little load speed for compatibility.

3. Verify in the network tab

Reload with DevTools open and check that the .br responses show Content-Encoding: br and the expected MIME type. A missing header here is the exact cause of the load failure.

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 HTML5 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.