While playing the game will randomly error and then proceed to close application. Once application is closed and error reported I am unable to enter the world again and cannot play the game I paid for

The game is so laggy to the point where my game errors and does not allow me to play on that world till a day later. It's gotten to the point where I want to refund the game since it's so bad. The nether update promised fist half of 2020 yet we are almost to June and still no new.