DaemonUmbra

How are you starting the server?

It's not supposed to be supported as 1.16 is out, but is in a grace period until 1.16 gets a recommended build of Forge, which keeps getting pushed back as Mojang threaten to release 1.16.2

Please don't Necro old threads, if you have an issue make your own.

1.12 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

I think so actually. Try removing Hwyla from the server and client, their config sync may be the issue.

Please keep this forum in English. What version of Minecraft are you using?

I recommend using Twitch only to install and manage packs but not run them, try the following: ⁠Install the pack via Twitch ⁠Install the version of Forge that the pack requires ⁠Make a new "Installation" in your launcher, setting its "Minecraft Version" to the correct version of Forge for the pack and setting its "Game Directory" to the folder that Twitch installed the modpack to ⁠Run the pack with the normal Minecraft Launcher

All I can really tell is something is mucking up a packet

I can't understand why there isn't more info in these logs

Can you send the server's debug.log as well?

No I mean did you restart in between getting the issue and sending the log, because restarting the client creates a new log

This log looks like a successful connection, albeit with many errors that mod devs are apparently happy to publish mods with Did you restart your client after getting the issue?

Try deleting your build folder and %USERPROFILE%/.gradle/caches/forge_gradle/minecraft_user_repo/net/minecraftforge/forge/forge-1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1

The debug.log you provided doesn't contain the exception you're reporting.

Do you have a solid grasp of Java?

1.12 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

1.12 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

Try removing Optifine

1.7 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

Why can't you provide a picture?

Those messages shouldn't have anything to do with you timing out, can you provide debug.log for both client and server using one of the sites in the "Logs" section of my signature below

No you have a COMPLETELY different issue. I recommend using Twitch to install and manage packs, but not to run them, follow the steps in the "Logs" section, "Twitch Launcher" subsection, of my signature below to run the pack without Twitch.

https://johann.loefflmann.net/en/software/jarfix/index.html

Who told you to set _JAVA_OPTIONS? Delete that environment variable. What is your JDK version?

Please provide debug.log using one of the sites listed in the "Logs" section of my signature below