Knowledge Base

Project Zomboid B42 – Server Fails to Start due to Out of Memory = TRUE

Summary

On Project Zomboid Build 42 (B42), dedicated servers running on machines with 8GB RAM or less may fail to start and throw a Java Memory Error during startup.

This is not a corruption or mod-related issue. It is caused by an overly aggressive default Java heap allocation that exceeds what the system can safely reserve.

Affected Systems

• Project Zomboid Build 42
• Equal or less than 8GB of RAM

Build 42 ships with a default Java configuration that includes:
-Xmx8g inside ProjectZomboid64.json file

Solution / Workaround
Edit file ProjectZomboid64.json inside your root folder

Find the line "-Xmx8g",

Change to something lower

Recommended values:
System RAM           Recommended Xmx
8GB                                 -Xmx6g
6GB                                 -Xmx4g
4GB                                  -Xmx3g

Save and restart the server