Solved Internal Error stopping player from joining

[Deimos]

Hello,

I've got a problem where a player is not able to join and they get this when they try to join,
Internal Exception: java.io.IOException: An existing connection was forcibly closed by the remote host

I also get this in the Console when they join.

[00:18:55] [Server thread/INFO]: Goldthorn777[/98.183.208.128:52504] logged in with entity id 31979153 at (-158.5, 65.0, 952.5)
[00:18:55] [Server thread/INFO]: Hatter joined the game
[00:18:55] [Server thread/WARN]: Failed to handle packet for /98.183.208.128:52504
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:?]
[00:18:55] [Server thread/INFO]: Goldthorn777 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}}
[00:18:55] [Server thread/INFO]: Hatter left the game

I've removed their .dat and all other files of theirs in the playerdata folder but still, they can not join.
Any ideas?

I am running DW20 1.7 1.0.3

 

[Deimos]

This issue has solved its self.

 

[Cheremenin]

I'm sorry for the bump, but how EXACTLY did it fix itself? Just randomly stopped happening after some time?

I'm having the same issue with a player on my private Resonant Rise 3 server, they just keep getting dropped with that error message. Nothing worked so far.

Feels like it could be related to their router, or something network-related on my server, but I just can't pinpoint it, randomly started happening out of nowhere.