What does this mean?

java.lang.OutOfMemoryError: GC overhead limit exceeded
at net.minecraft.server.v1_4_6.NibbleArray.<init>(SourceFile:9)
at net.minecraft.server.v1_4_6.ChunkSection.<init>(ChunkSection.java:17)
at net.minecraft.server.v1_4_6.ChunkRegionLoader.a(ChunkRegionLoader.java:299)
at net.minecraft.server.v1_4_6.ChunkRegionLoader.a(ChunkRegionLoader.java:94)
at net.minecraft.server.v1_4_6.ChunkRegionLoader.loadChunk(ChunkRegionLoader.java:83)
at org.bukkit.craftbukkit.v1_4_6.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:19)
at org.bukkit.craftbukkit.v1_4_6.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:13)
at org.bukkit.craftbukkit.v1_4_6.util.AsynchronousExecutor$Task.init(AsynchronousExecutor.java:150)
at org.bukkit.craftbukkit.v1_4_6.util.AsynchronousExecutor$Task.initAsync(AsynchronousExecutor.java:95)
at org.bukkit.craftbukkit.v1_4_6.util.AsynchronousExecutor$Task.run(AsynchronousExecutor.java:85)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

What does this mean and how do I fix it? My server keeps crashing because of it.

 

It means you have ran out of memory on your server or you have not enough disk space. Are you hosting this on your own computer or a hosting company is doing it for you?

 

A company is doing it for me. This never happened until I updated to the 1.4.6 dev build.

 

Well do you have access to viewing how much ram/disk space you have used? If you have maxed out, ask your company for more disk space or ram. The disk space should be free but you may have to upgrade for more ram.