Docker based Forge server - can't connect with CurseForge client but with "normal" Minecraft #3774

torstenbauer · 2025-11-24T19:04:49Z

torstenbauer
Nov 24, 2025

Hi,

tried to setup a docker based minecraft server with the following command:

docker run --name mc_server10 -it -p 25565:25565 -e EULA=TRUE -e TYPE=FORGE -e VERSION=1.21.10 -v /tmp/minecraft-data/mc_server/:/data itzg/minecraft-server

Startup:

[init] Running as uid=1000 gid=1000 with /data as 'drwxrwxrwx. 12 1000 1000 4096 Nov 23 13:32 /data'
[init] Image info: buildtime=2025-06-17T12:48:19.332Z,version=java21,revision=a5643cdeac3c1b3d61dbbba6f1136e04895bf613
[init] Resolving type given FORGE
�[39m[mc-image-helper] 18:51:47.537 INFO : Forge version 60.1.0 for minecraft version 1.21.10 is already installed
�[0;39m[init] Copying any mods from /mods to /data/mods
[init] Copying any configs from /config to /data/config
�[39m[mc-image-helper] 18:51:51.185 INFO : Created/updated 1 property in /data/server.properties
�[0;39m[init] Setting initial memory to 1G and max to 1G
[init] Using Forge supplied run.sh script...
�[32m[18:51:54] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher running: args [--launchTarget, forge_server]
�[m�[32m[18:51:54] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: JVM identified as Eclipse Adoptium OpenJDK 64-Bit Server VM 21.0.7+6-LTS
�[m�[32m[18:51:54] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher 10.2.4 starting: java version 21.0.7 by Eclipse Adoptium; OS Linux arch amd64 version 4.18.0-553.40.1.el8_10.x86_64
�[m�[32m[18:51:54] [main/INFO] [ne.mi.fm.lo.ImmediateWindowHandler/]: ImmediateWindowProvider not loading because launch target is forge_server
�[m�[32m[18:51:54] [main/INFO] [mixin/]: SpongePowered MIXIN Subsystem Version=0.8.7 Source=jar:file:///data/libraries/org/spongepowered/mixin/0.8.7/mixin-0.8.7.jar!/ Service=ModLauncher Env=SERVER
�[m�[32m[18:51:54] [main/INFO] [ne.mi.fm.lo.mo.JarInJarDependencyLocator/]: No dependencies to load found. Skipping!
�[m�[32m[18:51:55] [main/INFO] [cp.mo.mo.LaunchServiceHandler/MODLAUNCHER]: Launching target 'forge_server' with arguments []
�[m�[32m[18:52:00] [modloading-worker-0/INFO] [ne.mi.co.ForgeMod/FORGEMOD]: Forge mod loading, version 60.1.0, for MC 1.21.10 with MCP 20251007.101210
�[m�[32m[18:52:00] [modloading-worker-0/INFO] [ne.mi.co.MinecraftForge/FORGE]: MinecraftForge v60.1.0 Initialized
�[m�[32m[18:52:00] [modloading-worker-0/INFO] [ne.mi.co.ForgeMod/FORGEMOD]: Opening jdk.naming.dns/com.sun.jndi.dns to java.naming
�[m�[32m[18:52:00] [Forge Version Check/INFO] [ne.mi.fm.VersionChecker/]: [forge] Starting version check at https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json
�[m�[32m[18:52:01] [Forge Version Check/INFO] [ne.mi.fm.VersionChecker/]: [forge] Found status: UP_TO_DATE Current: 60.1.0 Target: null
�[m�[32m[18:52:01] [main/INFO] [mojang/YggdrasilAuthenticationService]: Environment: Environment[sessionHost=https://sessionserver.mojang.com, servicesHost=https://api.minecraftservices.com, profilesHost=https://api.mojang.com, name=PROD]
�[m�[32m[18:52:03] [main/INFO] [minecraft/RecipeManager]: Loaded 1461 recipes
�[m�[32m[18:52:03] [main/INFO] [minecraft/AdvancementTree]: Loaded 1574 advancements
�[m�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Starting minecraft server version 1.21.10
�[m�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Loading properties
�[m�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Default game type: SURVIVAL
�[m�[32m[18:52:04] [Server thread/INFO] [minecraft/MinecraftServer]: Generating keypair
�[m�[?1h�=�[?2004h>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Starting Minecraft server on *:25565
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/ServerConnectionListener]: Using epoll channel type
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Preparing level "world"
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/LoggingLevelLoadListener]: Loading 0 persistent chunks...
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/LoggingLevelLoadListener]: Time elapsed: 11 ms
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Done (0.376s)! For help, type "help"
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/DedicatedServer]: Starting remote control listener
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/GenericThread]: Thread RCON Listener started
�[m>....
�[K�[32m[18:52:04] [Server thread/INFO] [minecraft/RconThread]: RCON running on 0.0.0.0:25575
�[m>....
�[K�[33m[18:52:05] [LanServerPinger #1/WARN] [minecraft/LanServerPinger]: LanServerPinger: Network is unreachable
�[m>....
�[K�[32m[18:52:05] [Server thread/INFO] [ne.mi.se.pe.PermissionAPI/]: Successfully initialized permission handler forge:default_handler

My son can connect with the normal Minecraft client but not with CurseForge.

Any tip?

Thanks
Torsten

itzg · 2025-11-24T19:35:39Z

itzg
Nov 24, 2025
Maintainer

Can you clarify what happens when CurseForge client fails to connect?

Speaking of CurseForge, the image has automated support for retrieving modpacks for the server side

https://docker-minecraft-server.readthedocs.io/en/latest/types-and-platforms/mod-platforms/auto-curseforge/

In that case you don't need to explicitly refer to Forge modloader and the versions needed for the modpack.

5 replies

torstenbauer Nov 24, 2025
Author

I have no client available - need to ask my son tomorrow.. but it was like getoptsock failed or so in the client. And on the server side no connection is seen. With the standard minecraft client he was able to join the server and I've saw it also in the log.

Hmm, I tried auto curseforge yesterday but it failed to start and came up with many errors and didn't started at all

The current server I've created above has no mods or resources available. Me copied a few onto the server and as it was not working I've deleted them again to see if a connect is possible or not. I tried it also with a fresh data directory in the container and not assigning the one we used in another build.

torstenbauer Nov 24, 2025
Author

That was my try with AUTO_CURSEFORGE:

docker run --name mc_server16 -it -p 25565:25565 -e EULA=TRUE -e CF_API_KEY='' -e TYPE=AUTO_CURSEFORGE -e CF_PAGE_URL=https://www.curseforge.com/minecraft/modpacks/all-the-mods-10 itzg/minecraft-server

It ended up with:

    JVM Flags: 2 total; -Xmx1G -Xms1G
    ModLauncher: 11.0.5+main.901c6ea8
    ModLauncher launch target: forgeserver
    ModLauncher services:
            sponge-mixin-0.15.2+mixin.0.8.7.jar mixin PLUGINSERVICE
            loader-4.0.42.jar slf4jfixer PLUGINSERVICE
            loader-4.0.42.jar runtime_enum_extender PLUGINSERVICE
            at-modlauncher-10.0.1.jar accesstransformer PLUGINSERVICE
            loader-4.0.42.jar runtimedistcleaner PLUGINSERVICE
            modlauncher-11.0.5.jar mixin TRANSFORMATIONSERVICE
            modlauncher-11.0.5.jar fml TRANSFORMATIONSERVICE
            modlauncher-11.0.5.jar crash_assistant TRANSFORMATIONSERVICE
    FML Language Providers:
            [email protected]
            [email protected]
            [email protected]
            [email protected]
            [email protected]
    Mod List:
            server-1.21.1-20240808.144430-srg.jar             |Minecraft                     |minecraft                     |1.21.1              |Manifest: NOSIGNATURE
            neoforge-21.1.215-universal.jar                   |NeoForge                      |neoforge                      |21.1.215            |Manifest: NOSIGNATURE

[21:10:28] [main/ERROR] [minecraft/Main]: Failed to start the minecraft server
net.neoforged.fml.ModLoadingException: Loading errors encountered:
- Mod colorwheel requires iris 1.8.0 or above
Currently, iris is not installed

    at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.ModLoader.gatherAndInitializeMods(ModLoader.java:110) ~[loader-4.0.42.jar%2359!/:4.0] {}
    at TRANSFORMER/[email protected]/net.neoforged.neoforge.internal.CommonModLoader.begin(CommonModLoader.java:49) ~[neoforge-21.1.215-universal.jar%23557!/:?] {re:classloading}
    at TRANSFORMER/[email protected]/net.neoforged.neoforge.server.loading.ServerModLoader.load(ServerModLoader.java:34) ~[neoforge-21.1.215-universal.jar%23557!/:?] {re:classloading}
    at TRANSFORMER/[email protected]/net.minecraft.server.Main.main(Main.java:124) ~[server-1.21.1-20240808.144430-srg.jar%23556!/:?] {re:classloading}
    at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source) ~[?:?] {}
    at java.base/java.lang.reflect.Method.invoke(Unknown Source) ~[?:?] {}
    at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:136) ~[loader-4.0.42.jar%2359!/:4.0] {}
    at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.serverService(CommonLaunchHandler.java:128) ~[loader-4.0.42.jar%2359!/:4.0] {}
    at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonServerLaunchHandler.runService(CommonServerLaunchHandler.java:32) ~[loader-4.0.42.jar%2359!/:4.0] {}
    at MC-BOOTSTRAP/[email protected]/net.neoforged.fml.loading.targets.CommonLaunchHandler.lambda$launchService$4(CommonLaunchHandler.java:118) ~[loader-4.0.42.jar%2359!/:4.0] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:30) [modlauncher-11.0.5.jar%2364!/:?] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53) [modlauncher-11.0.5.jar%2364!/:?] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71) [modlauncher-11.0.5.jar%2364!/:?] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.run(Launcher.java:103) [modlauncher-11.0.5.jar%2364!/:?] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.Launcher.main(Launcher.java:74) [modlauncher-11.0.5.jar%2364!/:?] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) [modlauncher-11.0.5.jar%2364!/:?] {}
    at MC-BOOTSTRAP/[email protected]/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) [modlauncher-11.0.5.jar%2364!/:?] {}
    at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:210) [bootstraplauncher-2.0.2.jar:?] {}
    at [email protected]/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:69) [bootstraplauncher-2.0.2.jar:?] {}

2025-11-24T21:10:28.943Z INFO mc-server-runner Done

itzg Nov 24, 2025
Maintainer

There's an example for atm10

https://github.com/itzg/docker-minecraft-server/blob/master/examples/auto-curseforge/atm10/docker-compose.yml

torstenbauer Nov 25, 2025
Author

Thanks for that. Tried it but still problem with Iris 1.8.0

�[1;31m[18:17:37] [main/ERROR] [minecraft/Main]: Failed to start the minecraft server
net.neoforged.fml.ModLoadingException: Loading errors encountered:
- Mod colorwheel requires iris 1.8.0 or above
Currently, iris is not installed

itzg Nov 25, 2025
Maintainer

You must be running an old image. Re-pull and apply such as with

docker compose pull
docker compose up -d

At this point you'll also need to set the environment variable CF_FORCE_SYNCHRONIZE to "true".

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Docker based Forge server - can't connect with CurseForge client but with "normal" Minecraft #3774

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