Minecraft crashes when playing servers

I use minecraft:windows10 edition to play a server, and when I was palying the server, I found i couldn't move my mouse pointer. And then my computer got to stutter, then it crashed. A few days later, the same situation happened again. I had to force the game to close. The crash happened about five times in a week. Some days later, I opened the game, and it crashed again, but this time I was not playing the server. After it recovered, the lag became more serious. I reinstalled the game, the lag disappeared. One of my friend who also palys the minecraft:windows10 edition in his laptop had the same experience. And he also reinstalled the game to avoid the unbelievable lag.