Server and Client not connecting

[Magor362]

Steps to reproduce

• Installed a Neoforge Server with the neoforge installer

• downloaded my modpack, modified it for Server use (no client side mods, and a few server side ones).
  https://modrinth.com/modpack/weich-server-modpack (unlisted and not intended for public use)

• added custom cobblegen config, which does work (atleast in Fabric 1.21.1, both client and server)

• did start the server and (after other issues with unremoved client mods) started without major visible issues

• tried connecting with the client side of the modpack over localhost, but got the mentioned Issue

error log about the connection

modlist.txt

Client side onscreen error message

Expected behavior

connecting of the client to the server without an error

Actual behavior

Error with message on Client:
Internal Exception: java.lang.UnsupportedOperationException: Payload cobblegen:ping_server may not be sent to the client!

Crash logs

latest.log

Mod version

[NEOFORGE MC1.21+] v5.3.10-BETA

Game version

1.21.1

Modloader

NeoForge

Other details

There is no problem connecting with cobblegen unlisted as a mod on the Server side

Acknowledgements

• I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open issue.
• I have written a short but informative title.
• I have updated the mod to version 5.3.10.
• I have admitted that I am a clown by having checked this box, as I have not read these acknowledgements.
• I have filled out all of the requested information in this form.

[null2264]

Sorry for the delay, finally got a time to debug, seems like NeoForge changed the way Minecraft handle networking on 1.20.x, I'll try to fix it ASAP.

[null2264]

Should be fixed in v5.3.12

[Magor362]

it works if installed both on Server and client, if only installed on the Server, this error comes up:
disconnect-2024-11-04_01.06.06-client.txt

[null2264]

When you say "installed" you mean only the server got the updated mod (v5.3.12)?

Judging from the log, it seems like it is installed on client but not the updated version. I can't workaround it unfortunately since it's NeoForge internal's behaviour, so client also need to update the mod...

[Magor362]

you are right, i forgot the old installation because of the cryptic old name.

It works now with no version installed on the client flawlessly

[null2264]

Yeah, I messed up the filename on v5.3.10.

Glad that it's fixed now 👍