// modpack server guide
FTB StoneBlock 4 server hosting & setup guide
An FTB StoneBlock 4 server needs Java 21 and about 10–12 GB of RAM for up to 8 players.
FTB's underground survival pack for NeoForge 1.21.1: the world is solid stone, and you dig out a base, explore handmade vaults and work through quests.
Pack details checked by hand against FTB StoneBlock 4 on FTB on October 12, 2026.
FTB StoneBlock 4 is a NeoForge modpack for Minecraft 1.21.1 with 413 mods, 388 of which run on the server. We'd pick our Heavy plan (12 GB) for it.
- FTB says the pack needs enable-command-block=true in server.properties; without it, some structures in the world don't work properly.
Quick facts
| Loader | NeoForge |
|---|---|
| Minecraft versions | 1.21.1 |
| Java needed | Java 21 for Minecraft 1.21.1 Java version chart. |
| Mods | 388 run on the server413 in the pack. The other 25 are client-only, and the server skips them. Counted from FTB's file list for version 1.23.0. |
| RAM | About 9–9.5 GB for 1–3 playersBy player count. |
| Downloads | 2,136,220 on the FTB appAs of October 12, 2026. |
| Latest version | October 12, 2026 (version 1.23.0)The newest version when we checked on October 12, 2026. |
| Official server files | Download pageFTB publishes server files for every version on the pack's Versions tab and in its server files browser. |
| Authors' RAM advice | FTB's launcher setting for this pack is 8 GB recommended and 6 GB minimum, for the game.Source |
| Where to get it | FTB StoneBlock 4 on FTB |
| Tags | exploration, combat / pvp, magic, tech, quests |
FTB StoneBlock 4 on a server: what to know
FTB StoneBlock 4 is a NeoForge 1.21.1 underground survival pack: everyone starts in the Garden of Stone, picks one of five starting islands, and progresses by upgrading the World Engine and clearing Vaults. Version 1.23.0 (12 October 2026) uses NeoForge 21.1.250 and Java 21. FTB ships servers through its Server Installer rather than a zip. The installer reads the pack and version from its file name, so don't rename it (or pass -pack 130 -version <id>), and it downloads its own Java unless you add -no-java, which you'll want on a host that already provides Java 21. FTB uses the installer so it can hotfix pack files without releasing a new version, and the installer picks those fixes up.
On first start the pack's default-server.properties sets allow-flight=true, allow-nether=false, enable-command-block=true and spawn-protection=512.
Watch out for
- spawn-protection=512 keeps non-op players from changing a 1,025-block square around spawn, but Minecraft turns spawn protection off while the server has no ops, so op an admin. Source.
- FTB Backups 3 backs up every 2 hours and keeps 12; put changes in world/serverconfig/ftbbackups3-server.snbt so pack updates don't overwrite them. Source.
Sources: feed-the-beast.com, api.feed-the-beast.com, docs.feed-the-beast.com, github.com, files.feed-the-beast.com, files.feed-the-beast.com (2), github.com (2), minecraft.wiki. Checked October 12, 2026.
FTB StoneBlock 4 server files
FTB StoneBlock 4's authors publish official server files. FTB publishes server files for every version on the pack's Versions tab and in its server files browser. Get the official server files.
Use the server files for the exact version your players install: a server and client on different pack versions won't connect.
How much RAM does an FTB StoneBlock 4 server need?
| Players online | RAM | DSN plan |
|---|---|---|
| 1–3 players | About 9–9.5 GB | Heavy (12 GB) |
| 4–8 players | About 10–12 GB | Heavy (12 GB) |
| 9–15 players | About 11.5–14.5 GB | Heavy (12 GB) if players stay closeMore than 12 GB if they spread out. |
Estimated from 388 mods with our RAM calculator, set against the authors' own advice, not measured: low end if players stay together, high end if they spread out. What the authors say: FTB's launcher setting for this pack is 8 GB recommended and 6 GB minimum, for the game.
With 9–15 players spread across the map, FTB StoneBlock 4 can need more than 12 GB, our biggest plan. A lower view distance and a pre-generated world help it fit; past that, a host with bigger plans is the better choice.
Set Java's heap (-Xmx) 10–15% under the RAM you have, about -Xmx10500M on 12 GB. NeoForge 1.21.1 reads it from user_jvm_args.txt: uncomment the -Xmx line. RAM guide.
FTB StoneBlock 4 server requirements
| Java | Java 21 |
|---|---|
| Loader | NeoForge for Minecraft 1.21.1 |
| CPU | Fast single-core speed (one main thread). With 388 mods, the first start takes minutes. |
| RAM | About 9–14.5 GB for 1–15 players (table above) |
| Disk | The server files, a growing world and backups |
| Network | TCP port 25565 open to players |
Recommended plan
Our pick for FTB StoneBlock 4
Heavy
12 GB RAM · planned launch price $42/month
With 388 server-side mods and FTB recommending 8 GB for the game alone, 12 GB gives the server room for its players' chunks too.
Ordering is closed until we relaunch. We aren't taking orders or payments while we move to new hardware. Join the launch list and we'll email you when Heavy servers open.
Heavy is our biggest plan. Not sure? Email hello@dsnservers.com.
Planned launch price in USD, billed monthly once ordering opens, with a 7-day refund window.
How to make an FTB StoneBlock 4 server on your own PC
What's specific to FTB StoneBlock 4, step by step. The full walkthrough for any pack: how to make a modded Minecraft server.
- Install Java 21.
Check with
java -version. Java version chart. - Get the server files.
Download the official server files for the version your players use and unzip them into an empty folder. Follow the readme that comes with them.
- Start it and accept the EULA.
Run the start script in the server files, or the
run.sh/run.batthe NeoForge 1.21.1 installer writes, then seteula=trueineula.txtif you accept Mojang's EULA (EULA step). With 388 mods, the first start takes minutes. - Set the RAM with
-Xmx, sized from the table above. - Let friends connect: forward TCP 25565, or use a tunnel or host behind CGNAT (can't connect?).
Or run FTB StoneBlock 4 on DSN
Once we relaunch (join the launch list), on DSN you'd install FTB StoneBlock 4 from the panel's CurseForge modpack installer, pick Java 21 on the Startup tab and accept the EULA in the console. No port forwarding.
How to play FTB StoneBlock 4 with friends
Each player installs FTB StoneBlock 4 with the FTB App, the same version as the server, and adds the server's address under Multiplayer. The authors' memory advice for the game: FTB's launcher setting for this pack is 8 GB recommended and 6 GB minimum, for the game.
Different versions of FTB StoneBlock 4 on the server and a client show up as Mismatched mod channel list or mod rejections. Why friends can't join, timeouts included.
Lag and performance on FTB StoneBlock 4
Can't keep up! Is the server overloaded? means ticks take longer than 50 ms; more RAM won't fix that once FTB StoneBlock 4 has enough (tick lag guide). For FTB StoneBlock 4:
- Measure first: spark's
/spark tpsand profiler work on 1.21.1 and name the mod or machine using the tick time. - Distances:
view-distance=8and a lowersimulation-distanceinserver.properties. - Pre-generate: Chunky for 1.21.1,
/chunky radius 3000then/chunky start, before people explore. - Chunk loaders keep machines running with nobody nearby; in a pack this size, dozens add up.
Common FTB StoneBlock 4 crashes
What a NeoForge 1.21.1 server running FTB StoneBlock 4 hits most. For any other error, paste the log into the free crash log analyzer.
- Out of memory. FTB StoneBlock 4 (388 mods) needs about 9–9.5 GB for 1–3 players;
java.lang.OutOfMemoryErrormeans it ran out. Out-of-memory fix. - Wrong Java version. FTB StoneBlock 4 on Minecraft 1.21.1 needs Java 21. Started on Java 17, it stops with
UnsupportedClassVersionError: ... class file version 65.0, this version of the Java Runtime only recognizes class file versions up to 61.0. Java version fix. - Client-only mod on the server. FTB StoneBlock 4 includes 25 client-only mods, which a server install skips; copying a player's mods folder brings them back and stops the server. Check a mods list with the client-or-server-side checker. Client-only mod fix.
- After adding or updating a mod. Mods you add to FTB StoneBlock 4 by hand usually crash it with a missing dependency or a mixin conflict.
- Ticking entity or block entity. The crash report names it and gives its coordinates. Ticking entity fix.
Updates and support
Before moving FTB StoneBlock 4 past version 1.23.0, back up the world: see updating a modpack server without losing your world.
Bugs in FTB StoneBlock 4 itself go to its authors: issue tracker and wiki. Server problems on DSN: hello@dsnservers.com or Discord.
Packs like FTB StoneBlock 4
More: NeoForge server hosting, all modpack guides and how to make a modded server.
Run FTB StoneBlock 4 on DSN when we relaunch.
Our pick, Heavy: 12 GB, planned at $42/month.
DSN Servers isn't affiliated with FTB StoneBlock 4 or FTB. We wrote the summary and checked the pack's facts by hand on October 12, 2026. Sources: feed-the-beast.com, api.feed-the-beast.com, curseforge.com, api.cfwidget.com, api.feed-the-beast.com (2).