Can't play any 1.14 snapshots

I can't play any 1.14 snapshot , the game allways keep crashing and never opens up the game. I tried do change JVM arguments to -Xmss320K and it opened once on 18w45a, but too laggy, and with 18w46a it dosn't work. I click play with normal JVM arguments, it loads, and I got a message: "The game stop working."