When spawning falling sand entities through command blocks with the /summon command using water or lava block ids, the entity is not rendered. In previous versions this would render the whole water/lava block instead (which could be used for things like spraying fountains). Lastly, water/lava is spawned when landing, the falling sand entity just isn't rendering.

command I was using ( /summon FallingSand 12.5 67 -5.5

)