Graphical Issue - Snow Golem is Invisible In Adventure Map

I unlocked "snow turrets" in and adventure map by activating redstone. Everything was normal except for the fact that two of the snow golems weren't there. With one, I attempted to create using snow, but when I placed it, it appeared and instantly disappeared. I checked to see if redstone had to do with it. I broke the wool surrounding it and then a snow golem appeared out of nowhere and fell out. The picture shown is the second invisible golem before attempting to do the same as before. No invisibility effect particles where there.