Minecraft 1.7.10 crashes when I attempt to open a world [duplicate]
You have probably played 1.8 in this launcher. Your problem is likely due to options.txt in the Minecraft folder file having a render distance set really high (because of 1.8). From what I read, "Minecraft doesn't validate that the render distance is a supported value before trying to use it (apparently)." -Source
Deleting the options.txt file is the fix for this crash for most people who experience it.