When i start a single player world or create a new one it would crash. The reason is "Starting intergraded server". I have a server but these crashes started happening even before my server. Thats the biggest reason why i made my server. The crash report will be attached. I also have this problem with minecraft 1.7.9, 1.7.4, and 1.7.2. it just wont let me add those to the versions thing.
Dupe of MC-51590