Install a Curseforge / Modrinth modpack on the Wisp panel

Introduction

A Minecraft modpack is a pre-configured set of mods (often 100-300) with harmonized configs, scripts and resource packs. Main platforms:

• Curseforge: the best-known, integrated with launchers like CurseForge App
• Modrinth: open-source alternative, growing in popularity, faster

The Wisp panel (panel.verycloud.fr) supports both and automates installation. This guide shows both methods: automatic (recommended) and manual (if auto-install fails).

Prerequisites

• A Minecraft server ordered on VeryCloud (Wisp panel) with at least 6 GB RAM for a medium modpack
• For large modpacks (200+ mods): 8 to 16 GB RAM
• Curseforge or Modrinth modpack ID
• A Java Minecraft license (to test locally)

Step 1: Identify the modpack and version

On Curseforge or Modrinth, note:

• Exact name of modpack (e.g. "All the Mods 9", "Better MC", "Vault Hunters")
• Minecraft version (e.g. 1.20.1, 1.21)
• Loader: Forge, NeoForge or Fabric
• Recommended version of modpack (usually latest stable)

On Curseforge, the Project ID is in the URL: https://www.curseforge.com/minecraft/modpacks/all-the-mods-9 → look for "Project ID" in the right sidebar.

On Modrinth, it's in https://modrinth.com/modpack/SLUG → SLUG is the identifier.

Step 2: Automatic method via Wisp

On https://panel.verycloud.fr, select your server.

On Wisp, open "Egg" or "Server Type"

Wisp often provides a "Modpack Installer" egg that handles automatically:

1. Click Settings → Reinstall Server
2. Choose type Modpack (or similar based on your Wisp version)
3. Fill in:
   • Modpack source: Curseforge or Modrinth
   • Modpack ID: copied from step 1
   • Version: version number (e.g. 0.4.50)
4. Click Reinstall

Wisp downloads the modpack, Forge/Fabric/NeoForge installer and configures everything automatically (5-15 minutes depending on size).

Step 3: Manual method (if auto-install fails)

Some custom modpacks aren't in the auto catalog. Proceed via SFTP.

From Curseforge

1. Download the modpack from CurseForge App (Windows/Mac) or directly the "Server Pack" .zip from the site
2. In the ZIP, you find:
   • mods/: folder with mod .jar files
   • config/: mod configurations
   • forge-X.Y.Z.jar or fabric-server-launch.jar or installer.jar
   • startserver.bat / startserver.sh
   • eula.txt
3. Connect to your Wisp server's SFTP (panel → Server → SFTP details, usually port 2022) with FileZilla / WinSCP
4. Delete existing server files
5. Upload all Server Pack content

From Modrinth

Modrinth modpacks use the .mrpack format (but Wisp can often extract automatically).

If manual: convert with Modrinth-Pack-Converter or download the "server" version if offered.

Step 4: Verify and launch

In the Wisp panel:

1. Console → Startup → Edit:
   • Make sure the target .jar is correct (forge-X.Y.Z.jar or equivalent)
   • JAR file: the appropriate Forge/Fabric/NeoForge .jar
   • Allocated Memory: bump to 6G, 8G or more based on modpack
2. Click Start Server in console

First boot takes 3-10 minutes (world generation + mod initialization). Watch the logs.

Step 5: Allocate proper RAM

Critical for modpacks. Recommendations:

In Wisp: Settings → Resources → Memory.

Step 6: Configure mods server-side

Many mods have different server vs client configurations. Config files are in config/.

Frequent examples:

Optimize tickrate with FerriteCore / Krypton

For Fabric modpacks:

config/
├── ferritecore.json
└── krypton.json

Check they're present (no manual tuning needed, just their presence improves performance).

Disable server-incompatible mods

Some mods are client-side only (shaders, advanced GUIs, mini-maps). They may crash if they try to load server-side.

In mods/, move client-only mods to a mods-disabled/ folder:

mkdir mods-disabled
mv mods/JEI-*.jar mods-disabled/   # JEI works server-side, but example
mv mods/optifine-*.jar mods-disabled/  # Optifine = client only

Classically client-only mods:

• Optifine, Sodium, Iris (shaders/render optimizations)
• JourneyMap, Xaero's Minimap (maps - sometimes both-sided)
• WAILA/Jade, Just Enough Items (sometimes)
• Controllable, Better Advancements (UI)

Step 7: Pre-generate the world (recommended)

Modpacks generate tons of complex chunks. Pre-generating before players arrive avoids lag.

Install Chunky (Forge/Fabric/NeoForge compatible mod):

/chunky world overworld
/chunky radius 1000
/chunky start

Chunky pre-generates a 1000-block radius around spawn (4 million chunks). Depending on the server, allow 30 min to 4 hours.

Meanwhile, put the server in whitelist mode:

/whitelist on

Step 8: Automatic backups

Configure Wisp for daily backups:

Panel → Backups → Schedule:

• Daily at 4 AM
• Retention: 7 days
• Include worlds, mods, configs

For very large modpacks, do manual backups before each mod update — more cautious.

Troubleshooting

"Cannot find main class"

The startup .jar is wrong. Inspect:

ls *.jar

You should see forge-X.Y.Z-server.jar or similar. Adjust Startup → JAR file in Wisp.

Crash on startup: "Mixin apply failed"

Conflict between two mods. Open the full log and look for Mixin apply failed for: <ModA>. Disable ModA or look for a compatible version.

"Java heap space" / OutOfMemoryError

Not enough RAM allocated. Increase in Wisp Settings → Resources → Memory.

For large modpacks: add JVM flags in Startup → Java Arguments:

-Xms4G -Xmx12G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200

"Server-side mod required" client-side

Server has mods the client doesn't. Solution: send your players the modpack manifest.json or ask them to install the modpack via CurseForge App / Modrinth App, which auto-syncs.

Massive lag with ATM9 / Vault Hunters

Disable PortalAPI, optimize forge.toml:

[server]
    serverEventLoopGroupSize = "auto"
    tickrate = 20

And use Spark (mod) to identify resource-heavy mods:

/spark profiler --timeout 300

Useful commands

# View performance (with Spark mod installed)
/spark tps
/spark profiler

# Force a save
/save-all flush

# Pre-generate world
/chunky start

# View loaded chunks
/forge tps
/forge entitylist
/forge mods

Conclusion

You have a modpack server running on the VeryCloud Wisp panel. Some best practices going forward:

• Update mods sparingly (one buggy mod can break everything)
• Backup before every update
• Communicate exact modpack versions to your players
• Use Discord to announce restarts and maintenance

Modpacks demand lots of resources: if your current Wisp server isn't enough, VeryCloud offers more powerful Ryzen Gaming VPS or Dedicated plans.

Resources

• VeryCloud Wisp Panel: https://panel.verycloud.fr
• Curseforge Modpacks: https://www.curseforge.com/minecraft/modpacks
• Modrinth Modpacks: https://modrinth.com/modpacks
• Chunky (pre-generation): https://modrinth.com/mod/chunky
• Spark (performance): https://spark.lucko.me