package net.glowstone.io.entity;

import net.glowstone.entity.passive.GlowWolf;
import net.glowstone.util.nbt.CompoundTag;
import org.bukkit.DyeColor;
import org.bukkit.entity.EntityType;

class WolfStore extends TameableStore<GlowWolf> {

    public WolfStore() {
        super(GlowWolf.class, EntityType.WOLF);
    }

    @Override
    public void load(GlowWolf entity, CompoundTag compound) {
        super.load(entity, compound);
        if (compound.isByte("CollarColor")) {
            entity.setCollarColor(DyeColor.getByDyeData(compound.getByte("CollarColor")));
        }
        if (compound.isByte("Angry")) {
            entity.setAngry(compound.getBool("Angry"));
        }
    }

    @Override
    public void save(GlowWolf entity, CompoundTag tag) {
        super.save(entity, tag);
        tag.putByte("CollarColor", entity.getCollarColor().getDyeData());
        tag.putBool("Angry", entity.isAngry());
    }

}

package net.glowstone.io.entity;

import net.glowstone.entity.passive.GlowWolf;
import net.glowstone.util.nbt.CompoundTag;
import org.bukkit.DyeColor;
import org.bukkit.entity.EntityType;

class WolfStore extends TameableStore<GlowWolf> {

    public WolfStore() {
        super(GlowWolf.class, EntityType.WOLF);
    }

    @Override
    public void load(GlowWolf entity, CompoundTag compound) {
        super.load(entity, compound);
        entity.setCollarColor(DyeColor.getByDyeData(compound.getByte("CollarColor")));
        entity.setAngry(compound.getBool("Angry"));
    }

    @Override
    public void save(GlowWolf entity, CompoundTag tag) {
        super.save(entity, tag);
        tag.putByte("CollarColor", entity.getCollarColor().getDyeData());
        tag.putBool("Angry", entity.isAngry());
    }

}

--- 
+++ 
@@ -14,8 +14,12 @@
     @Override
     public void load(GlowWolf entity, CompoundTag compound) {
         super.load(entity, compound);
-        entity.setCollarColor(DyeColor.getByDyeData(compound.getByte("CollarColor")));
-        entity.setAngry(compound.getBool("Angry"));
+        if (compound.isByte("CollarColor")) {
+            entity.setCollarColor(DyeColor.getByDyeData(compound.getByte("CollarColor")));
+        }
+        if (compound.isByte("Angry")) {
+            entity.setAngry(compound.getBool("Angry"));
+        }
     }
 
     @Override
Fix exception when spawning Wolf from egg
