Set up Cracker's Wither Storm Performance

Cracker's Wither Storm Performance is a small Minecraft 1.20.1 Forge modpack by the CurseForge author kesselot. It pairs Cracker's Wither Storm Mod, which adds the Wither Storm boss from Minecraft: Story Mode, with performance mods so the fight runs smoothly. You install the server from the Modpacks tab, using the pack's CurseForge server pack.

Checked against Cracker's Wither Storm Performance 1.1.7 (the CurseForge file dated 9 October 2026) on Forge 47.4.20 and Minecraft 1.20.1, with Cracker's Wither Storm Mod 4.2.1, October 2026.

What the pack needs

• Minecraft 1.20.1 with Forge 47.4.20. The server pack's variables.txt names both. Minecraft 1.20.1 runs on Java 17, which the panel picks for you.
• Memory. The pack's page gives no RAM figure, and the server pack holds 26 mod jars. Your plan sets the RAM, so see how much RAM a Minecraft server needs and the Minecraft plans. The mod's wiki warns that the Wither Storm can cause large amounts of lag, so leave headroom.
• Disk space. The server pack is a download of about 77 MB and unpacks to about 86 MB.
• The same pack version for players. Players install Cracker's Wither Storm Performance 1.1.7 from the CurseForge app.

Install the server

1. Open your server and choose Modpacks under Content in the left rail.
2. Above the search box, press the CurseForge chip, then search for Cracker's Wither Storm Performance.
3. Pick Cracker's Wither Storm Performance by kesselot and press Install. Other packs with similar names are different projects. The popup says it reinstalls your server with the pack and names Forge and Minecraft 1.20.1.
4. Leave Take a backup first ticked. Your current world is replaced by the pack's. Tick Start the server when it's ready if you want it to start itself, and tick I agree to the Minecraft EULA if the popup shows it.
5. Press and hold Hold to Install and reinstall until it fills, then wait for the install to finish.

The pack ships no Forge files of its own, so the install reads variables.txt and sets up Forge 47.4.20 itself.

First start

Press Start on the Console tab. If the EULA has not been accepted yet, the panel asks you to accept it first. The server is up when the console prints a line containing For help, type. Your address is in the left rail under Server address. Connect to your server for the first time covers adding it in Minecraft, and joining a modded server from a launcher covers the client side.

Summoning and tuning the boss

The mod's page and its progression guide both say to find the rundown house at X: 0, Z: 0 and place the wither skulls on its incomplete wither-like structure. The mod's wiki also lists an operator command to start a storm at a chosen phase from 0 to 7, /summon witherstormmod:wither_storm ~ ~ ~ {Phase:0}, and /witherstormmod phase get @w to read the current phase. To use commands, make yourself an operator on the Players tab (whitelist and operators).

The page warns that the mod completely changes how you play and says it does not recommend summoning the storm on an existing world if that is your only copy and you care about it. Create a backup on the Backups tab first.

To change how fast it grows, start the server once so the world exists, then open the world's serverconfig/witherstormmod-server.toml in File Manager and edit evolutionAttributeModifier. The mod's own config text says a higher value makes the Wither Storm take longer to evolve from phase 0 to 7 and a lower value makes it quicker, with a range of 0.01 to 32 in version 4.2.1. Restart the server afterwards, since the mod's page says the world must be reloaded for the change to apply. The world folder is world unless you changed World folder in Config Editor. If the server's TPS drops in the later phases, the wiki suggests turning on Squash Hitboxes in the server config, with some drawbacks.

Common problems

• A player cannot join. Check they run the same pack file on Minecraft 1.20.1 with Forge, then compare their mod list with the server's mods folder.
• The server lags near the boss. Watch the RAM card on the Console tab and the TPS reading in the left rail. Why is my server lagging has more.
• The server crashes at boot. Find and read a crash report shows how to name the mod at fault.