From c0b99f356c30002ae8fb2536b5e0b78a7b8bfc4c Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 19 Jul 2018 01:08:05 -0400
Subject: [PATCH] Re-add vanilla entity warnings for duplicates

These are a critical sign that somethin went wrong, and you've lost some data....

We should kind of know about these things you know.

diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index c08ee62e84..85a30652c4 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -963,7 +963,8 @@ public class WorldServer extends World implements IAsyncTaskHandler {
                     this.g.remove(entity1);
                 } else {
                     if (!(entity instanceof EntityHuman)) {
-                        // WorldServer.a.warn("Keeping entity {} that already exists with UUID {}", EntityTypes.getName(entity1.P()), uuid.toString()); // CraftBukkit
+                        WorldServer.a.error("Keeping entity {} that already exists with UUID {} - " + entity1, EntityTypes.getName(entity1.P()), uuid.toString()); // CraftBukkit // Paper
+                        WorldServer.a.error("Deleting duplicate entity {}", entity); // Paper
                         return false;
                     }
 
-- 
2.21.0