further error debugging

src/main/java/me/km/snuviscript/ScriptEvents.java

@@ -715,9 +715,29 @@ public class ScriptEvents implements BlockHarvest, Craft {
     @SubscribeEvent(receiveCanceled = true)
     public void onMobGriefing(EntityMobGriefingEvent e) {
         handleEvent(e, "mob_griefing", (sc) -> {
-            setEntity(sc, e.getEntity());
-            sc.setVar("cancel",
-                    !e.getEntity().world.getGameRules().getBoolean(GameRules.MOB_GRIEFING));
+            Entity ent = e.getEntity();
+            setEntity(sc, ent);
+            if(ent != null) {
+                World w = ent.world;
+                if(w != null) {
+                    GameRules rules = w.getGameRules();
+                    if(rules != null) {
+                        boolean b = true;
+                        try {
+                            b = !rules.getBoolean(GameRules.MOB_GRIEFING);
+                        } catch(Exception ex) {
+                            ex.printStackTrace();
+                        }
+                        sc.setVar("cancel", b);
+                    } else {
+                        System.out.println("Rules are null");
+                    }
+                } else {
+                    System.out.println("World is null");
+                }
+            } else {
+                System.out.println("Entity is null");
+            }
         }, (sc) -> {
             handleVar(sc, "mob_griefing", "cancel", (v) -> {
                 e.setResult(v.getBoolean(sc) ? Result.DENY : Result.ALLOW);