Problematic code:
	if(TrailFX)
	{
		UParticleSystemComponent* TrailPSC = UGameplayStatics::SpawnEmitterAtLocation(this, TrailFX, Origin);
		if(TrailPSC)
		{
			static FName Param = FName(TEXT("InitVelocity"));
			TrailPSC->SetVectorParameter(Param, AdjustVec);
		}
	}
I pretty much just copied what has been in ShooterExample, to test out idea for projectile trail for trace hit weapon.
In any case, I just run out of idea why it might not work. From what I see, it’s defined and initialized