java.lang.ClassNotFoundException: net.minecraft.world.World
[12:56:38] [main/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
[12:56:38] [main/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at java.lang.ClassLoader.loadClass(Unknown Source)
[12:56:38] [main/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at java.lang.ClassLoader.loadClass(Unknown Source)
[12:56:38] [main/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: ... 13 more
This typically means there is a conflict with another mod. What mod i dont know. Your debug log is full of information that isnt needed (a typical log is normally fine and less then half the size) so I am yet to find the mods you are running.
All i can say at the moment is to try the fixes on “Common Crash Fixes” such as foamfix and renaming your sponge file