when I summon vex,polar bears,wolfs,llamas,bats,lligars,ender dragon,ocalots,villagers,zombie pig men,and much more

what i was expecting when i downloaded MINECRAFT!!!!!! was to have fun but in stead when i summon newley relecesd mobs it crashes and said that ht there as a fatal error detcted by te jarva runtime envronment after summoning some cretures and when a shulker shoots a bullet at me and i go into the end then it crashes