After just finishing a fight in the sea temple I was hanging out on an island sorting out my inventory when the game crashed so when logged back into my world I had been put back 10 minutes and better yet I had lost all my achievements and as a acomplishist  I am of course pretty mad.

I also tried restarting my PC and it did not work so this is clearly a bug having to do with Minecraft. another thing that happens often is the game just randomly crashing with a message that goes "Code 0".