Frequently asked questions
Answers to the issues most likely to appear during a beginner installation.
How do I start Jarock?
Run start-server.bat in the repository root. Do not double-click server/server.jar. On first start, choose Fabric or NeoForge and optionally open the parameter manager.
Why does the first run stop?
It may need the Minecraft EULA. Open server/eula.txt, read the official EULA, set eula=true only if you agree, and run the launcher again.
Why does Java 25 appear missing?
Jarock validates the exact executable and rejects older or unusable candidates. Install a 64-bit Java 25+ JDK, reopen the terminal, or put the JDK folder/path to bin\java.exe in java-home.txt.
Should I choose Fabric, Forge, or NeoForge?
Choose Fabric first. Choose NeoForge only when a required compatible mod needs it. Forge is displayed for transparency but is unavailable until an official Minecraft 26.2 server build is verified.
Can I use Bukkit or Paper plugins?
Not automatically. Fabric and NeoForge use their native mod ecosystems. A hybrid compatibility layer is not enabled by default and cannot guarantee plugin compatibility.
Does Jarock open router ports?
No. Jarock is local-first and does not modify routers, firewall rules, or port forwarding. Configure public Java TCP and Bedrock UDP networking manually only after completing the security checklist.
Why can Java connect but Bedrock cannot?
Check that Geyser and Floodgate are loaded, that the Bedrock UDP port is correct and distinct from the Java TCP port, and that firewall/host/router rules allow it. Test from another device before publishing the server.
When should I run cleanup?
Stop the server, back up the world, then run clean-server-runtime.bat before a clean reinstall or loader switch. See the cleanup detail page.
What should I do after an error?
Read the first ERROR: and Suggested fix:. If Java started, inspect server/logs/latest.log and crash reports. Do not delete the world before creating a backup. If the message is unclear, open an issue with the exact output.