When I start my Bukkit server this pops up repeatedly. Whats wrong?

14:27:36 [INFO] Chunk file at -6,2 is in the wrong location; relocating. (Expected -6, 2, got -4, 9)
14:27:36 [INFO] Chunk (-4, 9) stored at (-6, 2)
14:27:36 [SEVERE] java.lang.Throwable
14:27:36 [SEVERE] at org.bukkit.craftbukkit.util.LongHashtable.put(LongHashtable.java:19)
14:27:36 [SEVERE] at net.minecraft.server.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:75)
14:27:36 [SEVERE] at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:255)
14:27:36 [SEVERE] at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:148)
14:27:36 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:335)
14:27:36 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)
14:27:36 [INFO] Chunk (-4, 9) stored at (-6, 2)
14:27:36 [SEVERE] java.lang.Throwable
14:27:36 [SEVERE] at org.bukkit.craftbukkit.util.LongHashtable.get(LongHashtable.java:32)
14:27:36 [SEVERE] at net.minecraft.server.ChunkProviderServer.getOrCreateChunk(ChunkProviderServer.java:116)
14:27:36 [SEVERE] at net.minecraft.server.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:102)
14:27:36 [SEVERE] at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:255)
14:27:36 [SEVERE] at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:148)
14:27:36 [SEVERE] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:335)
14:27:36 [SEVERE] at net.minecraft.server.ThreadServerApplication.run(SourceFile:422)

 

Get this tool.
Then watch this video to learn how to use it.

It will fix the chunk error.

 

i have a mac will that make a difference?