Singleplayer literally unplayable due to stalling

Ever since the last 2 updates, I've been experiencing single player stalling to an insane degree. I can't hit mobs, block breaks hardly work, and opening chests is impossible. I often get "disconnected from server" errors too, to the point I can only play for a minute before everything breaks. Why does hytale force you to run a server off your PC if you're playing in singleplayer?