I have been playing a lot of a big adventure map, and it's been having craaazy lag lately. I figure it's because it's got a lot of big builds and I use a bunch of big mods, and this isn't a gaming pc, so i decide to play vanilla. I create a new world, but then i get stuck on the loading screen. I have to force quit the game, and then when i reload, the new world is there and works fine. It's incredibly annoying and I have no idea what's going on??