OK, so first off I was playing single player and I was in my house's basement and I hear a VERY loud and weird noise. So I go to check it out upstairs and its like over 300 skeletons burning on fire I have NO IDEA how they got there, but they did. I turn my difficulty to peaceful just to get rid of them all. Then I save and quit and then re-join the game and I start falling into the void. I wait for a little bit and 1 chunk loads. It's my house and nothing more I waited another 30 min and another chunk loads. When I exit the game I have to reload all the chunks I loaded before. I'm very confused and would love some help I got very far on this world and would be upset if I lost it. Any advise would be great, Thanks.
Is my minecraft world corrupt? PLEASE HELP 1.3.1