I am trying running a server with the recommended build of Forge for 1.12.2, and no mods. It seems to work when I join server for the first time, but after I disconnect I am unable to reconnect. The server outputs the following when I try to reconnect:

[Server thread/INFO] [minecraft/NetHandlerPlayServer]: SillyPutty lost connection: Internal Exception: io.netty.handler.codec.EncoderException: java.io.IOException: Can't serialize unregistered packet

I can run a server for 1.8.9 with mods without any issues, but can't seem to get this version to work. Any ideas on how I can resolve this issue? Thanks!

 

Forge version: forge-1.12.2-14.23.5.2768 (also tested with 2775)

debug.log

Sometimes I'm able to get: 

Quote

java.io.IOException: An established connection was aborted by the software in your host machine

when I disconnect after my first connection. I still get the same error when I try to reconnect. Here's the log file

 

Also, I should add that this problem does not exist for vanilla minecraft servers. If I run the "minecraft_server.1.12.2.jar" that comes with the forge executable file, everything works fine. The problem is specific to forge, and it's on the server side. My java is updated, and I can connect to the server on the same computer using my LAN IP address, or from a different computer. I'm just not sure what to try next.

 

EDIT: Here's one more log where I was able to connect twice before it stops letting me in.

 

Edited November 21, 20186 yr by SillyPutty125
extra log

You could start an issue on the Forge GitHub if you think this is a real bug (which it seems to be)

 

Do you have any mods or anything installed? How are you running the sever? 

No mods except for forge. I'm running the server with the following batch file:

java -Xms512M -Xmx4096M -d64 -jar forge-1.12.2-14.23.5.2768-universal.jar nogui
pause

 

I'll open an issue on GitHub if people are confident I'm not doing something stupid.

You should probably do a little bit more digging first.

Do you have any other networking related stuff going on on your network/computer? Are you port forwarding your sever?

Most importantly, does it work on another machine or account?

4 minutes ago, Cadiboo said:

Do you have any other networking related stuff going on on your network/computer? Are you port forwarding your sever?

I'm behind a router, but I have port forwarding setup (works perfectly for 1.8.9). The problem exists regardless of whether I connect to my router's IP, or my computer's IP (192.168.0.2)

 

4 minutes ago, Cadiboo said:

Most importantly, does it work on another machine or account?

Yeah, it's at least somewhat unique to my machine. I had a friend test it out on a different machine/network/account and it worked fine. I can personally test it out on another machine tomorrow.

Try adding -Dforge.logging.mojang.level=debug to the server run arguments (and possibly also your client JVM arguments) and then supply a debug.log file with that setting enabled to get more info than just "Can't serialize unregistered packet".

Edited November 21, 20186 yr by quadraxis
update

13 hours ago, quadraxis said:

Try adding -Dforge.logging.mojang.level=debug to the server run arguments (and possibly also your client JVM arguments) and then supply a debug.log file with that setting enabled to get more info than just "Can't serialize unregistered packet".

Here's my log for the server with debugging turned on. I'll get back to you on the debug logs for client side. 

Here's the log from the client side

I tested with other computers yesterday. The problem is definitely with running a server on this particular computer (running windows 7). I can't reproduce the problem with a server on another machine.

 

To summarize:

• I have a machine that cannot host a 1.12.2 minecraft server using forge (no mods), but it can host 1.12.2 vanilla and 1.8.9 forge/vanilla without issue.
• The error message is "Can't serialize unregistered packet" when attempting to join the server from any machine. The client only sees "Disconnected: Failed to connect to the server."
• Joining the server always works the first time after server startup, and almost always fails the second time. After failing to join once it always fails every subsequent attempt.
• Java is up to date, and the server is running the latest recommended build of forge. (forge-1.12.2-14.23.5.2768)
• The problem persists with firewalls and antivirus disabled.
• I have port forwarding setup properly, though tests have also be performed on a LAN.

Here's a snippet from the server debug.log:

[02:14:48] [User Authenticator #2/DEBUG] [com.mojang.authlib.HttpAuthenticationService]: Opening connection to https://sessionserver.mojang.com/session/minecraft/hasJoined?serverId=-51d4d3928be0b8be72f5948347df120e37886337&username=SillyPutty
[02:14:48] [User Authenticator #2/DEBUG] [com.mojang.authlib.HttpAuthenticationService]: Reading data from https://sessionserver.mojang.com/session/minecraft/hasJoined?serverId=-51d4d3928be0b8be72f5948347df120e37886337&username=SillyPutty
[02:14:48] [User Authenticator #2/DEBUG] [com.mojang.authlib.HttpAuthenticationService]: Successful read, server response was 200
[02:14:48] [User Authenticator #2/DEBUG] [com.mojang.authlib.HttpAuthenticationService]: Response: {"id":"f1dd241ea1c84b5eaede23924d8c2017","name":"SillyPutty","properties":[{"name":"textures","value":"eyJ0aW1lc3RhbXAiOjE1NDI3OTUyODU5MDcsInByb2ZpbGVJZCI6ImYxZGQyNDFlYTFjODRiNWVhZWRlMjM5MjRkOGMyMDE3IiwicHJvZmlsZU5hbWUiOiJTaWxseVB1dHR5IiwidGV4dHVyZXMiOnsiU0tJTiI6eyJ1cmwiOiJodHRwOi8vdGV4dHVyZXMubWluZWNyYWZ0Lm5ldC90ZXh0dXJlLzg4YzU2OTY1YjVkOTQyZDliMmQ2NDdkMDc1NWRiNWJlM2UwNzRjMDE3ZjMyOGEzMTRiOGI0MzIwZTgxOWJjYTEifX19","signature":"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"}]}
[02:14:48] [User Authenticator #2/INFO] [net.minecraft.server.network.NetHandlerLoginServer]: UUID of player SillyPutty is f1dd241e-a1c8-4b5e-aede-23924d8c2017
[02:14:48] [Server thread/TRACE] [FML]: Handshake channel activating
[02:14:48] [Server thread/DEBUG] [FML]: FMLHandshakeServerState: null->FMLHandshakeServerState$1:START
[02:14:48] [Server thread/DEBUG] [FML]:   Next: HELLO
[02:14:48] [Server thread/DEBUG] [net.minecraft.network.NetworkManager]: Set listener of net.minecraft.network.NetworkManager@5ab9cdf5 to net.minecraftforge.fml.common.network.handshake.NetworkDispatcher$1@1b71594
[02:14:48] [Server thread/DEBUG] [net.minecraft.network.NetworkManager]: Enabled auto read
[02:14:48] [Netty Server IO #5/DEBUG] [net.minecraft.network.NetworkManager]: Internal Exception: io.netty.handler.codec.EncoderException: java.io.IOException: Can't serialize unregistered packet
io.netty.handler.codec.EncoderException: java.io.IOException: Can't serialize unregistered packet
	at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:125) ~[MessageToByteEncoder.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:738) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:801) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.invokeWriteAndFlush(AbstractChannelHandlerContext.java:804) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:814) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:794) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:831) ~[AbstractChannelHandlerContext.class:?]
	at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:1032) ~[DefaultChannelPipeline.class:?]
	at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:296) ~[AbstractChannel.class:?]
	at net.minecraft.network.NetworkManager$4.run(NetworkManager.java:245) [gw$4.class:?]
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) [AbstractEventExecutor.class:?]
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403) [SingleThreadEventExecutor.class:?]
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:442) [NioEventLoop.class:?]
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [SingleThreadEventExecutor$5.class:?]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_191]
Caused by: java.io.IOException: Can't serialize unregistered packet
	at net.minecraft.network.NettyPacketEncoder.encode(NettyPacketEncoder.java:42) ~[ha.class:?]
	at net.minecraft.network.NettyPacketEncoder.encode(NettyPacketEncoder.java:12) ~[ha.class:?]
	at io.netty.handler.codec.MessageToByteEncoder.write(MessageToByteEncoder.java:107) ~[MessageToByteEncoder.class:?]
	... 16 more

 

Does anyone have any ideas on what I should check/try next?

This thread might be useful, try using 64 bit Java (you have 86 bit 1.8.0_191 and are running it on a 64-Bit Server VM).

https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

Edited November 24, 20186 yr by Cadiboo

26 minutes ago, Cadiboo said:

This thread might be useful, try using 64 bit Java (you have 86 bit 1.8.0_191 and are running it on a 64-Bit Server VM).

https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

Thank you! I was able to fix the problem by uninstalling my 32 bit Java, forcing it to use the 64 bit version. I don't know why it was using the 32 bit version to begin with!