diff --git a/src/main/java/net/minecraft/server/WorldData.java b/src/main/java/net/minecraft/server/WorldData.java index 292cb56142..bef6a94fdf 100644 --- a/src/main/java/net/minecraft/server/WorldData.java +++ b/src/main/java/net/minecraft/server/WorldData.java @@ -1,6 +1,7 @@ package net.minecraft.server; import java.util.List; +import org.bukkit.Bukkit; public class WorldData { @@ -46,6 +47,10 @@ public class WorldData { this.worldUID = (System.nanoTime() << 20) + this.a; nbttagcompound.setLong("WorldUID", this.worldUID); } + + if (Bukkit.getServer().getWorld(worldUID) != null) { + throw new IllegalStateException("World '" + name + "' contains a conflicting UID with existing world. Please edit its level.dat and remove WorldUID, or delete its level.dat (and lose its seed/etc)."); + } // CraftBukkit end }