[11:53:02 WARN]: Exception in thread "Craft Scheduler Thread - 273"
[11:53:02 WARN]: org.apache.commons.lang.UnhandledException: Plugin Sandbot v3.1-Beta generated an exception while executing task 43
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IllegalStateException: Asynchronous entity world add!
        at org.spigotmc.AsyncCatcher.catchOp(AsyncCatcher.java:12)
        at net.minecraft.server.v1_8_R3.World.b(World.java:3882)
        at net.minecraft.server.v1_8_R3.Chunk.addEntities(Chunk.java:918)
        at org.bukkit.craftbukkit.v1_8_R3.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:52)
        at org.bukkit.craftbukkit.v1_8_R3.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:1)
        at org.bukkit.craftbukkit.v1_8_R3.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:337)
        at org.bukkit.craftbukkit.v1_8_R3.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:295)
        at org.bukkit.craftbukkit.v1_8_R3.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:17)
        at net.minecraft.server.v1_8_R3.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:137)
        at net.minecraft.server.v1_8_R3.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:119)
        at org.bukkit.craftbukkit.v1_8_R3.CraftWorld.getChunkAt(CraftWorld.java:145)
        at org.bukkit.craftbukkit.v1_8_R3.CraftWorld.getBlockAt(CraftWorld.java:91)
        at me.elapsed.plugin.sandbot.runnables.CacheSpawn.run(CacheSpawn.java:51)
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:63)
        at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
        ... 3 more