1.8 game crash java.lang.IllegalArgumentException

When I attempt to run my very simple mod, I get this crash report:

"java.lang.IllegalArgumentException: Can not set static com.arti.artismod.ArtisMod field com.arti.artismod.ArtisMod.instance to com.example.examplemod.ExampleMod"

The code:

package com.arti.artismod;

import net.minecraftforge.fml.common.Mod;

import net.minecraftforge.fml.common.Mod.EventHandler;

import net.minecraftforge.fml.common.Mod.Instance;

import net.minecraftforge.fml.common.event.FMLInitializationEvent;

import net.minecraftforge.fml.common.event.FMLPostInitializationEvent;

import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;

@Mod(modid = ArtisMod.MODID, name = ArtisMod.MODNAME, version = ArtisMod.VERSION)

public class ArtisMod {

    public static final String MODID = "tutorial";

    public static final String MODNAME = "Tutorial Mod";

    public static final String VERSION = "1.0.0";

    @Instance

    public static ArtisMod instance = new ArtisMod();

    @EventHandler

    public void preInit(FMLPreInitializationEvent e) {

    }

    @EventHandler

    public void init(FMLInitializationEvent e) {

    }

    @EventHandler

    public void postInit(FMLPostInitializationEvent e) {

    }

}