Annoying bugs with UMG focus (with Is Focusable? on all widgets false)

[Ixiguis]

Update: in more recent UE versions, you just have to add this to your PlayerController’s BeginPlay:

void AMyPlayerController::BeginPlay()
{
	Super::BeginPlay();

	if (IsLocalPlayerController())
	{
		TSharedRef<FNavigationConfig> Navigation = MakeShared<FNavigationConfig>();
		Navigation->bKeyNavigation = false;
		Navigation->bTabNavigation = false;
		Navigation->bAnalogNavigation = false;
		FSlateApplication::Get().SetNavigationConfig(Navigation);
	}
}

No need to create a new input processor.