Why does Minecraft crash Minecraft?

Answer 1

The game often crashes for a couple of reasons, actually. One is that you may be on a multiplayer server and the server gets too full. That causes the game to have too much data to take in to memorize, resulting in crashes. Another reason is that in single player, there might be a mod that has a bug, glitch or virus that will cause the game to crash. It could also mean the computer itself is going bananas. Check your computer's status before swearing at minecraft for crashing. Yet another reason is that you may have a software virus. Though uncommon, it never hurts to check before downloading any programs.

Answer 2

If you are trying to open MineCraft in two separate windows, the crash is caused because you are trying to login to the game with the same account but in different places. Your player can only be in one place at a time so trying to login more than once will confuse the game and cause it to crash. If this not an answer to the question that you asked, then try to be more specific when you ask a question.