mystcraft crash

[WARNING] Failed to handle packet: java.lang.NullPointerException
java.lang.NullPointerException
	at codechicken.nei.NEIServerUtils.isMagnetMode(NEIServerUtils.java:377)
	at codechicken.nei.ServerPacketHandler.handlePacket(ServerPacketHandler.java:56)
	at codechicken.core.PacketCustom$ServerPacketHander.handle(PacketCustom.java:98)
	at codechicken.core.PacketCustom$CustomPacketHandler.onPacketData(PacketCustom.java:47)
	at cpw.mods.fml.common.network.NetworkRegistry.handlePacket(NetworkRegistry.java:249)
	at cpw.mods.fml.common.network.NetworkRegistry.handleCustomPacket(NetworkRegistry.java:239)
	at cpw.mods.fml.common.network.FMLNetworkHandler.handlePacket250Packet(FMLNetworkHandler.java:78)
	at im.a(NetServerHandler.java:1065)
	at da.a(SourceFile:59)
	at bx.b(TcpConnection.java:441)
	at im.d(NetServerHandler.java:82)
	at in.b(NetworkListenThread.java:55)
	at hk.b(SourceFile:30)
	at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:664)
	at hg.r(DedicatedServer.java:241)
	at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:585)
	at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:492)
	at fp.run(SourceFile:818)