Busses and VCAs not found when running WebGL build

It’s my first time doing a Unity WebGL build. The the PC/Mac/Linux builds all work fine.

We have code that gets references to the master bus and a couple VCAs (and adjusts volumes on them). These lines appear to be the ones causing exception. This is the error from the JS console.

BusNotFoundException: [FMOD] Bus not found 'Bus:/'
  at FMODUnity.RuntimeManager.GetBus (System.String path) [0x00000] in <00000000000000000000000000000000>:0 
(Filename: currently not available on il2cpp Line: -1)

I’ve tried commenting out the line just to see what’d happen, and execution stopped instead at the next line.

VCANotFoundException: [FMOD] VCA not found 'vca:/Music'
  at FMODUnity.RuntimeManager.GetVCA (System.String path) [0x00000] in <00000000000000000000000000000000>:0 
(Filename: currently not available on il2cpp Line: -1)

So… anyone know anything?

With HTML5, bank loading is asynchronous, so it’s possible you are trying to grab the VCAs before the banks are ready. Check out the platform specific section of our Unity docs for some more info about presenting a loading scene while this happens.