Error log FTB

2014-02-21 22:53:46 [WARNING] [Minecraft-Server] The save is being accessed from another location, aborting
2014-02-21 22:53:46 [INFO] [Minecraft-Server] Saving chunks for level 'Direwolf 20 world'/Nether
2014-02-21 22:53:46 [INFO] [STDERR] net.minecraft.world.MinecraftException: The save is being accessed from another location, aborting
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.world.storage.SaveHandler.func_75762_c(SaveHandler.java:101)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.world.World.func_72906_B(World.java:4078)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.world.chunk.storage.AnvilChunkLoader.func_75816_a(AnvilChunkLoader.java:120)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.world.gen.ChunkProviderServer.func_73242_b(ChunkProviderServer.java:232)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.world.gen.ChunkProviderServer.func_73151_a(ChunkProviderServer.java:284)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.world.WorldServer.func_73044_a(WorldServer.java:899)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.func_71267_a(MinecraftServer.java:360)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:124)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:484)
2014-02-21 22:53:46 [INFO] [STDERR] at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:583)