Set up a Voltz server

Voltz is one of Technic's own modpacks. Its server download includes mods such as ICBM, Atomic Science, Mekanism, Galacticraft, MineFactory Reloaded and Modular Powersuits. It is an old pack: Technic's recommended build runs Minecraft 1.5.2. Technic publishes a ready-to-run server download for it, and the Modpacks tab installs that download through its Technic search source.

Checked against the Voltz server download v2.0.4 and Technic's recommended build 2.0.5 (Minecraft 1.5.2), October 2026.

What it needs

• Minecraft 1.5.2 with Forge. The server download carries its own launch jar, Voltz.jar, plus the Minecraft server jar, a mods folder and a coremods folder. The panel runs 1.5.2 on Java 8 by itself, so you do not pick a Java version.
• Memory. The pack's own launch.sh asks for 2 GB at the start and 3 GB at most. The panel does not run that script. It writes its own launch script and sizes memory from your plan. How much RAM does my Minecraft server need? and Minecraft hosting cover the choices.
• The Technic Launcher on every player's computer. Players install Voltz there and use the recommended build, 2.0.5. Technic's build list shows 2.0.5 is 2.0.4 plus one mod, Lumy Skin Patch, which restores player skins, so the two match as far as the server cares. Newer builds such as 3.1.2 run Minecraft 1.6.4 and do not match this server.

Install the pack

Installing a modpack reinstalls the whole server, so use a new server or one you can wipe.

1. Open Modpacks, under Content in the left rail. Press the Technic source button. With nothing typed, the tab lists Technic's own packs, and Voltz is one of them. You can also search for Voltz.
2. Press Install on Voltz. A pack with no server download shows No server download instead, and this one has one. The window that opens should read Forge, Minecraft 1.5.2.
3. Leave Take a backup first ticked, so the panel backs up your server before it installs. If the window shows a note about your world's Minecraft version in place of Keep my world, settings and player lists, your world is newer than 1.5.2, which cannot open it, so the pack starts a fresh world and your old one stays in the backup.
4. Press and hold Hold to Install and reinstall for about three seconds, until it fills, then watch the Console tab until the install finishes.

The panel downloads the pack's server zip from Technic, unpacks it, and reads the launch jar, Voltz.jar, from the pack's own launch.sh. It also puts the six library files this Forge version would otherwise try to download on its first run into a lib folder, so there is nothing to upload.

First start

Press Start on the Console tab and accept the Minecraft EULA if the panel asks. When the console prints a line containing For help, type, the server is up.

Share the address shown under Server address in the left rail (Connect to your server for the first time).

The download's server.properties has online-mode=true. Open Config Editor to change Server list message (it reads A Voltz Server) or Player slots, then restart.

Common problems

• The install says Technic has no server download. Technic did not answer, or the link changed. Nothing on your server changed, so try again in a few minutes.
• The install says "Couldn't start a backup. Free a backup slot, or untick the backup and try again." Delete a backup you no longer need under Backups (a protected backup has to be unprotected first), or untick Take a backup first, then try the install again.
• The server lags. Watch the RAM Usage card on the Console tab, and if it sits near your plan's limit, move to a bigger plan under Settings > Plan and game > Change plan.