9. Troubleshooting

If you are experiencing an issue with the integration and none of the topics below help, visit to our Q&A Forum.

9.1 Check the plugin is installed

You should see a shortcut to the manual is available under the help menu, that means the plugin is in the right place and has been enabled.

If you see the FMOD Help in the manual, then the plugin installed correctly. If you don't see FMOD help, it isn't installed.

9.2 Project Output Format

If you have modified the project output format in your FMOD Studio project, you will need to update your Unreal project settings to match.
This can be found under "Edit > Project Settings > FMOD Studio > Output Format". Keep in mind that this must match the Studio project settings in order for the mix to behave correctly.

9.3 Content Changes

The editor does not mark FMOD assets as read-only, so there is nothing stopping the user from trying to rearrange the folder structure.
However any such changes aren't going to change the underlying Studio project, so the changes will be lost next time Unreal is restarted.

9.3.1 Asset Paths

The inbuilt Unreal asset serialization stores asset by full path, not by GUID. This means that if you rename events or folders in the Studio Tool, then any references in Unreal levels will be lost. For now the only workaround is to avoid renaming events or folders once you have started using them in levels.

9.4 Deployment Issues

See the Deployment page for information about issues with deployment.

If you Launch your game and there is no sound playing or there is error loading the FMODStudio module, it an issue with Deployment.

9.5 Live Update

If Live Update is enabled and the FMOD Studio will error when it fails to open the required network port. If this is a problem, then Live Update can be disabled in the Project Settings window.

9.6 Additional Logging

To help track down problems, verbose logging can be turned on for FMOD For Unreal. Add the following command line to the Unreal editor:

-LogCmds="LogFMOD verbose"

9.7 Blueprint only projects

Packaging a blueprint only project containing FMOD for Unreal will result in an error:

"Plugin 'FMODStudio' failed to load because module 'FMODStudio' could not be found.

The only way to work around this is to add a blank code class to the project and build the resulting solution before packaging again.
This is mentioned by Epic on their forum: Unable to run plugins when packaged.

9.8 Audio not muted when game loses focus

FMOD will not automatically mute its audio output when your game loses focus due to the user hitting alt-tab or switching to a different app. If you would like to mute FMOD audio when your game loses focus, make an OnApplicationActivationStateChanged callback and write code to mute the FMOD master bus. Here is an example :

void AExampleGameMode::InitFMODFocusChangeCallback()
{
    FSlateApplication::Get().OnApplicationActivationStateChanged()
        .AddUObject(this, &AExampleGameMode::OnWindowFocusChanged);
}

void AExampleGameMode::OnWindowFocusChanged(bool bIsFocused)
{
#if !WITH_EDITOR
    if (IFMODStudioModule::IsAvailable())
    {
        FMOD::Studio::System* StudioSystem = IFMODStudioModule::Get().GetStudioSystem(EFMODSystemContext::Runtime);
        FMOD::Studio::Bus* masterBus;
        StudioSystem->getBus("bus:/", &masterBus);
        masterBus->setMute(!bIsFocused);
    }
#endif
}

9.9 EndPlay with Play-In-Editor

Normally cleaning up in EndPlay() is valid and safe to do for your game, but during Play-In-Editor EndPlay doesn't get triggered until after the FMODStudio Module has already been shutdown. This isn't such an issue with Studio API, as when the System gets released it cleans up all of it's managed handles. The issue is when using the Core API because you need to manage it's objects yourself.

We have a delegate that you can hook into, which will fire off a function before the FMOD System has been shutdown. You can access the delegate using IFMODStudioModule::Get().PreEndPIEEvent().

Eg.

void AMyActor::BeginPlay()
{
#if WITH_EDITOR
    IFMODStudioModule::Get().PreEndPIEEvent().AddUObject(this, &AMyActor::ShutdownFunction);
#endif
}

void AMyActor::EndPlay()
{
#if WITH_EDITOR
    IFMODStudioModule::Get().PreEndPIEEvent().RemoveAll(this);
#else
    ShutdownFunction();
#endif
}

void AMyActor::ShutdownFunction()
{
    if (channel)
    {
        channel->stop();
    }
    if (sound)
    {
        sound->release();
    }
}