All black, no chat, game frozen.

When I use the new launcher and join multiplayer (I'm sure this happens in singleplayer too) the blocks don't show up and the screen is all black or it has the stars and moon, I can't chat and it won't let me log out at all. When I go back to the old launcher the game runs smoother and this doesn't happen at all. Please fix this, it's an awful inconvenience.