Server null pointer exception server side, client gets kicked

I've been getting this error server side whenever I try to get on my own server:

Code:

20:04:36 [SEVERE] java.lang.NullPointerException
20:04:36 [SEVERE]       at net.minecraft.server.World.a(World.java:1393)
20:04:36 [SEVERE]       at net.minecraft.server.World.a(World.java:1366)
20:04:36 [SEVERE]       at net.minecraft.server.World.a(World.java:505)
20:04:36 [SEVERE]       at net.minecraft.server.MetadataChunkBlock.a(SourceFile:104)
20:04:36 [SEVERE]       at net.minecraft.server.World.doLighting(World.java:1354)
20:04:36 [SEVERE]       at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:365)
20:04:36 [SEVERE]       at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:287)
20:04:36 [SEVERE]       at net.minecraft.server.ThreadServerApplication.run(SourceFile:394)
20:04:36 [SEVERE] Unexpected exception
java.lang.NullPointerException
        at net.minecraft.server.World.a(World.java:1393)
        at net.minecraft.server.World.a(World.java:1366)
        at net.minecraft.server.World.a(World.java:505)
        at net.minecraft.server.MetadataChunkBlock.a(SourceFile:104)
        at net.minecraft.server.World.doLighting(World.java:1354)
        at net.minecraft.server.MinecraftServer.h(MinecraftServer.java:365)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:287)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:394)

The message it gives the client is:

Internal exception: java.net.SocketTimeoutException: read timed out

I'm running bukkit version 729

if any other information is needed that I left out, just post what you need. I really want to get this fixed as this is the better of my two servers. So thanks in advance(if you help me of course).