Logs:
[13:59:17] [user Authenticator #2/INFO]: UUID of player Fulagann is 00d64f75-44a1-4600-8c5e-967da33ca8a1
[13:59:18] [server thread/INFO]: Fulagann[/10.0.0.2:52584] logged in with entity id 1281 at (440.4902246942252, 65.23152379758702, -2208.876882721954)
[13:59:18] [server thread/INFO]: Fulagann (formerly known as Fuonline) joined the game
[13:59:18] [server thread/WARN]: Failed to handle packet for /##.#.#.#:52584
java.lang.NullPointerException
at cpw.mods.fml.common.network.internal.FMLProxyPacket.func_148833_a(FMLProxyPacket.java:101) ~[FMLProxyPacket.class:?]
at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212) ~[ej.class:?]
at net.minecraft.network.NetworkSystem.func_151269_c(NetworkSystem.java:165) [nc.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:659) [MinecraftServer.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:334) [lt.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685) [li.class:?]
[13:59:19] [server thread/INFO]: Fulagann lost connection: TextComponent{text='Internal server error', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null}}
[13:59:19] [server thread/INFO]: Fulagann left the game