| Parameter | Purpose | Recommended Value | |-----------|---------|-------------------| | -XX:+UseG1GC | Enables G1 Garbage Collector (lower latency) | Default for modern systems | | -XX:+UseStringDeduplication | Reduces memory footprint of duplicate strings | Enable | | -XX:+OptimizeStringConcat | Improves string handling performance | Enable | | -XX:+UseCompressedOops | Compresses object pointers in 64-bit JVM | Enable | | -Dfml.ignoreInvalidMinecraftCertificates=true | Bypasses mod certificate checks | Enable for modded play |
| Problem | Zulu/x64 Cause | Fix | | :--- | :--- | :--- | | "Java Runtime not found" | Steam installed 32-bit Zulu by mistake. | Navigate to Steam\steamapps\common\ProjectZomboid and run ProjectZomboid64.bat directly. | | Crash with "EXCEPTION_ACCESS_VIOLATION" | A mod is using JNI (Java Native Interface) incompatible with your x64 Zulu (e.g., a 32-bit native library). | Remove the offending mod. Check if it requires a specific x64 DLL. | | High RAM usage after hours of play | Zulu's G1GC hasn't released fragmented heap memory to the OS. | This is normal on x64. Use -XX:+UseShenandoahGC (if available) for better return-to-OS behavior. | | Server "OutOfMemoryError" | You are running 32-bit Zulu on the server (common on cheap VPS). | Force the server script to use the x64 JVM. java -d64 -version to check. | zulu platform x64 architecture project zomboid new
Troubleshooting "Zulu Platform x64 is Not Responding" Crashes | Parameter | Purpose | Recommended Value |