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Minecraft•January 21, 2026• 120 views

Resolve timeouts on a modded Minecraft server

Resolve timeouts on a modded Minecraft server

Understanding Timeouts

The Issue of Disconnections

Connection interruptions due to timeouts are one of the most common obstacles faced by players on Minecraft servers using substantial modpacks. The classic scenario: you start your game, try to join your favorite server, then after a long wait, the game abruptly sends you back to the main menu with a timeout error.

This issue generally originates from the time required to load the numerous mods and synchronize with the server. Fortunately, a few configuration adjustments or the installation of a suitable mod can effectively resolve these interruptions and ensure a stable connection.

Mechanism of Timeouts

Minecraft natively imposes a 30-second limit for critical operations: mod initialization, server connection establishment, synchronization data transfer. This duration is sufficient for a vanilla installation, but quickly becomes inadequate when mods come into play.

Root Causes of the Problem

Triggering Factors

Timeouts occur more frequently in the following situations:

Situation Impact
Voluminous modpack (100+ mods) Very High
Unstable or slow network connection High
Machine with limited resources (RAM/CPU) High
Mods requiring intensive processing Moderate
Saturated or poorly configured server Moderate

Quick Diagnosis

To identify the source of the problem, observe the displayed error message:

  • "Timed out" or "Read timed out" → Timeout issue
  • "Connection lost" → Network instability or timeout
  • Crash with stacktrace → Mod conflict or incompatibility
  • "Missing mod" → Mod missing on client or server side

Solutions by Modloader

The corrective method varies depending on the modding environment used. Forge/NeoForge and Fabric each have their own approaches.

Forge and NeoForge

Two strategies are available to you: manually adjusting JVM parameters or installing a specialized mod.

Method 1: JVM Arguments (Recommended)

This approach involves modifying the launch command to extend the timeout from 30 to 120 seconds.

Arguments to include:

-Dfml.readTimeout=120 -Dfml.loginTimeout=120

These parameters instruct Forge/NeoForge to allocate more time during loading and authentication phases, significantly reducing the risk of interruptions with substantial modpacks.

Placement of arguments:

# Correct structure
java -Dfml.readTimeout=120 -Dfml.loginTimeout=120 -Xms4G -Xmx8G -jar server.jar nogui

# Incorrect position (will not work)
java -Xms4G -Xmx8G -jar server.jar -Dfml.readTimeout=120 nogui

The arguments must be placed between java and -jar to be interpreted by the JVM.

Method 2: Mod TimeoutFixes

For those who prefer a solution without technical manipulation:

Recommended mod: TimeoutFixes

  • Compatible with Forge and NeoForge
  • Installation required on both server and client
  • Automatic configuration of timeouts

Link: https://www.curseforge.com/minecraft/mc-mods/timeoutfixes

Fabric

The Fabric ecosystem has its own dedicated solution, usually not requiring modification of JVM arguments.

Mod TimeOutOut

This mod allows adjusting and increasing connection timeouts to prevent disconnections during mod initialization.

Features:

  • Specifically designed for Fabric
  • Installation mandatory on both client and server in multiplayer
  • Flexible timeout settings

Link: https://www.curseforge.com/minecraft/mc-mods/timeoutout

Server Configuration

Access to Startup Parameters

The procedure varies depending on your hosting provider. Here is the general process applicable to most administration panels.

Step 1: Locate Startup Options

  1. Log in to your administration panel (OuiHeberg or other)
  2. Access the Settings or Configuration section
  3. Look for the Startup command or JVM arguments option

Step 2: Modify the Command

Identify the current command line and insert the timeout arguments.

Before modification:

java -Xms4G -Xmx8G -jar server.jar nogui

After modification:

java -Dfml.readTimeout=120 -Dfml.loginTimeout=120 -Xms4G -Xmx8G -jar server.jar nogui

Step 3: Apply the Changes

  1. Save the new configuration
  2. Perform a complete server restart
  3. Check the logs to confirm the parameter updates

Custom Startup Script

If you manage your own machine, create a dedicated startup script:

Linux (start.sh):

#!/bin/bash
java -Dfml.readTimeout=120 \
     -Dfml.loginTimeout=120 \
     -Xms4G \
     -Xmx8G \
     -XX:+UseG1GC \
     -XX:+ParallelRefProcEnabled \
     -XX:MaxGCPauseMillis=200 \
     -jar server.jar nogui

Windows (start.bat):

@echo off
java -Dfml.readTimeout=120 -Dfml.loginTimeout=120 -Xms4G -Xmx8G -jar server.jar nogui
pause

Client Configuration

Official Minecraft Launcher

Configuration Procedure

  1. Launch the Minecraft Launcher
  2. Go to the Installations tab
  3. Select the profile corresponding to your modpack
  4. Click on More options to expand the advanced settings

Adding Arguments

In the JVM Arguments field, add to the existing parameters:

Configuration type:

-Xms4G -Xmx8G -Dfml.readTimeout=120 -Dfml.loginTimeout=120

Save by clicking Save then launch the game with this profile.

Alternative Launchers

CurseForge

  1. Open the application's Settings
  2. Select the Minecraft section
  3. Locate the Additional Java Arguments field
  4. Insert: -Dfml.readTimeout=120 -Dfml.loginTimeout=120

Prism Launcher / MultiMC

  1. Right-click on the relevant instance
  2. Choose Edit or Edit Instance
  3. Access the Settings and Java tab
  4. Enter the arguments in the appropriate field

ATLauncher

  1. Access the Settings
  2. Open the Java/Minecraft tab
  3. Add the arguments in Extra JVM Arguments

GDLauncher

  1. Click on the settings icon (gear)
  2. Select Java
  3. Fill in the Additional Arguments field

Diagnostic and Advanced Troubleshooting

Verification of Parameter Application

To confirm that your modifications are effective, examine the startup logs.

Server side:

# Search in the logs
grep -i "timeout" logs/latest.log

Positive indicators:

  • Absence of "Timed out" messages during player connections
  • Longer but successful connection times

Gradual Adjustment of Values

If 120 seconds are insufficient for your configuration, proceed in increments:

Level Value Use case
Standard 120s Classic modpacks (50-100 mods)
Extended 180s Large modpacks (100-200 mods)
Maximum 240s Massive modpacks (200+ mods)
Extreme 300s Very slow configurations

Example with extended delay:

-Dfml.readTimeout=180 -Dfml.loginTimeout=180

Beyond 300 seconds, the issue is more related to optimizing the modpack or hardware resources rather than just the waiting time.

Error Logs Analysis

Common messages and interpretations:

Message Meaning Solution
io.netty.handler.timeout.ReadTimeoutException Read timeout exceeded Increase readTimeout
Login timed out Authentication too slow Increase loginTimeout
Connection reset Connection interrupted Check network stability
Internal Exception Internal error Consult complete stacktrace

Additional Optimizations

Performance Mods

Increasing timeouts is sometimes only a temporary solution. To address the issue at its source, install optimization mods.

ModernFix

Optimizes memory management and accelerates resource loading.

FerriteCore

Drastically reduces RAM consumption on large installations.

LazyDFU

Defers DataFixerUpper initialization, speeding up launch.

Network Stabilization

Mod Connectivity

Improves network connection management and reduces disconnections due to instability.

Known incompatibility: Connectivity cannot coexist with TimeoutFixes. Choose one or the other based on your main issue.

Server Network Configuration

server.properties Parameters

# Increase if necessary
max-tick-time=120000
network-compression-threshold=256

spigot.yml Parameters (if applicable)

settings:
  timeout-time: 120
  restart-on-crash: true

FAQ

Installation on client side, server side, or both?

Timeout management mods (TimeOutOut, TimeoutFixes) should be deployed on both the client and server for optimal compatibility. Partial installation can lead to unpredictable behavior.

Does increasing timeouts degrade performance?

Absolutely not. These settings only define the maximum wait time before considering an operation as failed. They do not influence CPU load, memory consumption, or bandwidth.

How to distinguish a timeout from other types of errors?

Timeout errors are characterized by explicit messages: "Timed out", "Connection lost", "Read timed out". A sudden crash with a complete error trace (stacktrace) indicates a mod conflict or incompatibility. A message mentioning a missing mod signals an incomplete installation.

Do these solutions apply to vanilla Minecraft?

The -Dfml.readTimeout and -Dfml.loginTimeout arguments are exclusively recognized by Forge and NeoForge. In a vanilla installation, they will simply be ignored. Timeouts in vanilla are rare and usually result from network issues.

Which timeout value to choose?

Start with 120 seconds, a value suitable for most configurations. If disconnections persist, increase in 60-second increments. Beyond 300 seconds, focus on optimizing the modpack rather than extending timeouts.

The issue persists despite all these modifications?

Several avenues to explore:

  1. Check the logs to confirm parameter application
  2. Test your network connection (ping, stability)
  3. Temporarily reduce the modpack to isolate a problematic mod
  4. Increase the allocated resources (especially RAM)
  5. Update all your mods to their latest versions

Solutions Recap

Forge / NeoForge

Method Difficulty Effectiveness
JVM Arguments Easy Excellent
Mod TimeoutFixes Very easy Very good
Mod Connectivity Very easy Good (network)

Fabric

Method Difficulty Effectiveness
Mod TimeOutOut Very easy Excellent

Universal Optimizations

Mod Function Impact
ModernFix General optimization High
FerriteCore RAM Reduction High
LazyDFU Quick Boot Moderate

Useful Resources

Documentation

Diagnostic Tools

Communities

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