I can't get into my world

I am In the nether in a nether fortress facing a nether rack block and then I want to leave my Minecraft world. I leave the world. Then I wait about 10-15 minutes. Then I want to play again. So I get into my Minecraft world and play. It loads just about all the way and then stops. After a minute I crash out of the Minecraft app. It is a survival world that I love. You can't say it freezes because the captions were still rotating. The seed is  1158507128. There is no cheats