Troubleshooting - LCK Documentation

Recording Issues

Recording doesn't start

Symptoms: StartRecording() returns but no recording begins.Solutions:

Verify the Tracking ID is set in Project Settings
Ensure a valid SceneCaptureComponent2D is registered
Check log for errors: LogLCK, LogLCKEncoding

// Verify capture component is registered
if (!Service->IsInitialized())
{
    UE_LOG(LogTemp, Error, TEXT("Service not initialized"));
}

Recording stops unexpectedly

Symptoms: Recording ends without calling StopRecording().Solutions:

Check OnRecordingError delegate for error messages
Verify disk space is available
Check for encoder errors in LogLCKEncoding

Service->OnRecordingError.AddDynamic(this, &AMyActor::HandleError);
void AMyActor::HandleError(FString Message, int32 Code)
{
    UE_LOG(LogTemp, Error, TEXT("Recording error %d: %s"), Code, *Message);
}

Poor video quality

Symptoms: Recording looks blurry or has artifacts.Solutions:

Increase video bitrate in recording settings
Use a higher quality profile (HD, 2K, 4K)
Check render target resolution matches recording resolution

// Ensure settings match your quality needs
Service->ApplyRecordingSettings(
    1920, 1080,  // Match render target
    30,
    12000000,    // HD default bitrate
    256000,
    48000
);

Video is black

Symptoms: Recording file is black but audio works.Solutions:

Verify SceneCaptureComponent2D is capturing
Check capture component has a valid render target
Ensure capture component is enabled and visible

// Verify capture is working
CaptureComponent->bCaptureEveryFrame = true;
CaptureComponent->CaptureScene();

Audio Issues

No audio in recording

Symptoms: Video records but audio is silent.Solutions:

Verify audio plugins are enabled
Check that audio sources are registered
Ensure audio permissions are granted (Android)

// Check audio sources
TArray<ILCKAudioSource*> Sources;
IModularFeatures::Get().GetModularFeatureImplementations<ILCKAudioSource>(
    ILCKAudioSource::GetModularFeatureName(), Sources);

if (Sources.Num() == 0)
{
    UE_LOG(LogTemp, Warning, TEXT("No audio sources!"));
}

Audio is distorted

Symptoms: Audio has crackling, popping, or pitch issues.Solutions:

Check sample rate matches between source and encoder
Verify buffer sizes are adequate
Check for CPU overload

// Match sample rates
int32 SourceRate = ULCKUnrealAudioBPL::GetUnrealAudioSamplerate();
Params.Samplerate = SourceRate;  // Must match

Microphone not working

Symptoms: Game audio records but no microphone.Solutions:

Check SetMicrophoneEnabled(true) is called
Verify microphone permissions (Android)
Check if another app is using the microphone

// Ensure mic is enabled
Service->SetMicrophoneEnabled(true);

// Verify
if (Service->IsMicrophoneEnabled())
{
    UE_LOG(LogTemp, Log, TEXT("Mic enabled"));
}

Platform Issues

Android encoding fails

Symptoms: Recording fails on Android devices.Solutions:

Ensure Vulkan is enabled — OpenGL ES is not supported for video encoding
Remove OpenGL ES from your project’s graphics API list
Check device supports hardware H.264 encoding
Verify RECORD_AUDIO permission is granted at runtime

; AndroidEngine.ini
[/Script/AndroidRuntimeSettings.AndroidRuntimeSettings]
bEnableVulkanSM5Support=True

Windows encoder not found

Symptoms: Recording fails with encoder initialization error.Solutions:

Verify Windows Media Foundation is available
Check GPU drivers are up to date
Ensure AVCodecsCore plugin is enabled

Meta Quest performance issues

Symptoms: Frame drops during recording on Quest.Solutions:

Reduce recording resolution to HD (1080p) or SD (720p)
Lower video bitrate
Reduce framerate to 30 FPS (SD default)
Vulkan must be enabled (required for encoding on Android)

UI Issues

Buttons don't respond

Symptoms: UI buttons don’t register touches.Solutions:

Verify collision profile is set correctly
Check button is visible and enabled
Verify interactor collision settings

// Ensure collision is set up
Button->CollisionBox->SetCollisionProfileName(
    FLCKConstants::UICollisionProfileName
);

UI not visible

Symptoms: UI components don’t appear.Solutions:

Call Show() on showable components
Check component is attached to visible actor
Verify materials are loaded

// Make sure to show UI
Button->Show();

Text overflow

Symptoms: Long text messages does not wrap**Solution: **Write shorter messages or add line breaks. There is no other solution at this time

Plugin Issues

Plugin not loading

Symptoms: Plugin features unavailable at runtime.Solutions:

Verify plugin is enabled in .uproject
Check module dependencies in Build.cs
Look for load errors in Output Log

// Verify in .uproject
{
  "Plugins": [
    { "Name": "LCK", "Enabled": true },
    { "Name": "LCKTablet", "Enabled": true }
  ]
}

Missing module dependencies

Symptoms: Linker errors or undefined symbols.Solutions: Ensure all required modules are listed:

PublicDependencyModuleNames.AddRange(new string[] {
    "LCKCore",
    "LCKAudio",
    "LCKUI",      // If using UI
    "LCKTablet"   // If using tablet
});

Diagnostic Commands

Enable Verbose Logging

; DefaultEngine.ini
[Core.Log]
LogLCK=VeryVerbose
LogLCKEncoding=VeryVerbose
LogLCKAudio=VeryVerbose
LogLCKUI=Verbose
LogLCKTablet=Verbose

Runtime Diagnostics

void AMyActor::DiagnoseLCK()
{
    // Check subsystem
    auto* Subsystem = GetWorld()->GetSubsystem<ULCKSubsystem>();
    UE_LOG(LogTemp, Log, TEXT("Subsystem: %s"),
        Subsystem ? TEXT("OK") : TEXT("MISSING"));

    // Check service
    auto* Service = Subsystem ? Subsystem->GetService() : nullptr;
    UE_LOG(LogTemp, Log, TEXT("Service: %s"),
        Service ? TEXT("OK") : TEXT("MISSING"));

    // Check recorder
    auto* Recorder = GetWorld()->GetSubsystem<ULCKRecorderSubsystem>();
    UE_LOG(LogTemp, Log, TEXT("Recorder: %s"),
        Recorder ? TEXT("OK") : TEXT("MISSING"));

    // Check audio sources
    TArray<ILCKAudioSource*> Sources;
    IModularFeatures::Get().GetModularFeatureImplementations<ILCKAudioSource>(
        ILCKAudioSource::GetModularFeatureName(), Sources);
    UE_LOG(LogTemp, Log, TEXT("Audio sources: %d"), Sources.Num());
}

Getting Help

If you can’t resolve an issue:

Enable verbose logging and capture the output
Note the exact error message and conditions
Join our Community Discord

​Recording Issues

​Audio Issues

​Platform Issues

​UI Issues

​Plugin Issues

​Diagnostic Commands

​Enable Verbose Logging

​Runtime Diagnostics

​Getting Help