the launcher won't let me play online, then when it tries to load a world, the whole game crashes

2 days ago, the game crashed while i was playing it.now the launcher won't load correctly and it won't go online. when i click "play offline" the game opens and seems to work fine until I try to open any world. the game says its loading the world, but then it crashes.

i sent this same complaint yesterday, but your stupid rep said that it was because i pirated the game. which is not true as i payed Mojang and downloaded the game from the Mojang Minecraft website.

i tried re-installing the game but all that downloads is the same broken launcher.

i also re-installed Java but that didn't seem to help either.

I would like to re-iterate that I purchased the game and downloaded it from your website and have been playing it just fine for over a year.