I have posted this error in the Smart Moving topic and Divisor says its a minecraft forge error when smart moving is installed. Any help with this would be great! Also, it doesn't seem to cause any problems, just a messy console. lol

 

Here is a link to the topic I have mentioned.

 

2012-11-01 15:01:45 [sEVERE] [ForgeModLoader] A critical server error occured handling a packet, kicking net.smart.moving.playerapi.NetServerHandler@79541d
java.lang.NullPointerException
at cpw.mods.fml.common.modloader.ModLoaderConnectionHandler.connectionClosed(ModLoaderConnectionHandler.java:42)
at cpw.mods.fml.common.network.NetworkRegistry.connectionClosed(NetworkRegistry.java:213)
at cpw.mods.fml.common.network.FMLNetworkHandler.onConnectionClosed(FMLNetworkHandler.java:315)
at bx.b(TcpConnection.java:449)
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)

2012-11-01 15:01:45 [WARNING] [Minecraft] Failed to handle packet: java.lang.NullPointerException
java.lang.NullPointerException
at cpw.mods.fml.common.modloader.ModLoaderConnectionHandler.connectionClosed(ModLoaderConnectionHandler.java:42)
at cpw.mods.fml.common.network.NetworkRegistry.connectionClosed(NetworkRegistry.java:213)
at cpw.mods.fml.common.network.FMLNetworkHandler.onConnectionClosed(FMLNetworkHandler.java:315)
at bx.b(TcpConnection.java:449)
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)

This is indeed a serious ML compatibility bug.

Line 42 of ModLoaderConnectionHandler is:

if (!ModLoaderHelper.sidedHelper.clientConnectionClosed(manager, mod))

 

This is within method connectionClosed(INetworkManager), who's javadocs clearly states it will be called on BOTH CLIENT AND SERVER (IConnectionHandler.java:56)

 

On the client side, ModLoaderHelper.sidedHelper is set to an instance of ModLoaderClientHelper upon said instance's construction. However, on the server side, ModLoaderHelper.sidedHelper is never set and defaults to null.

 

It may be notable that all usages of ModLoaderHelper.sidedHelper within the class ModLoaderHelper itself is guarded by null checks (ModLoaderHelper.java:127, ModLoaderHelper.java:159).

 

Hope this helps!

So is this a Minecraft forge problem or Smart Moving?

This is an issue with Forge ModLoader (so minecraft forge, in other words).

This problem only occurs when trying to run a ModLoader mod in a dedicated server context. Hence why it is very rarely seen.

It is fixed, but to be honest, ModLoader mods don't fit very well with a dedicated server context and I recommend switching to a mod design that is...

In order to go smp, modloader mods had to use modloadermp in the old days. ML was client side only.

So yeah, ML mods don't work on dedicated servers unless they use MLMP/forge/hacks.