To reproduce make a custom entity with the projectile component. Then add the lightning parameter and set it to "true". What happens is the lightning doesn't strike even if the other parameters work. Its suppose to strike the entity with lightning when they are hit with the projectile but this doesn't happen. It doesn't show any creator errors which is why I think its a bug. As you can see the lightning parameter is set to true. Unfortunately I cant show you what's suppose to happen as it doesn't work.