Game Crashes every time in 1.9

I have been playing the Minecraft 1.9 snapshot ever since it came out, but until about three weeks ago, I'd enter my game, open up singleplayer, and when I clicked on a world, it would load. After about four seconds (or more), it would automatically crash. I restarted my computer, closed and reopened Minecraft, tried all 1.9 versions, and have tried all my worlds to see if they crashed too. They did. If you could please help out with this, I would be extremely glad. Thank you for your consideration!