Client Crashes & Lag (Allocate More RAM)
If your game crashes to desktop or lags heavily with mods, it likely needs more RAM. You can fix this by editing the game configuration. Locate the ProjectZomboid64.json (Windows) or Info.plist (macOS) file and increase the -Xms (minimum RAM) and -Xmx (maximum RAM) values, e.g., to -Xms1800m and -Xmx4096m.
Paths: Windows (Steam\steamapps\common\ProjectZomboid\ProjectZomboid64.json), macOS (/Users/{Your_User}/Library/Application Support/Steam/steamapps/common/ProjectZomboid/Project Zomboid.app/Contents/Info.plist). WARNING: Don't allocate more than 3GB if you only have 8GB of system RAM! Remember to save the file. Game updates may reset these settings.
Read the full step-by-step Reddit guide →