How to create a server (kicks,mods,optimization,etc)

To host a co-op server in Project Zomboid without kicking your friend for high ping, you must edit the server configuration file used by the in-game Host option. The file is called servertest.ini. Before starting the server, open this file and set PingLimit to 300 (use 400–500 if your friend has very high ping), set MaxPlayers to the number you want, keep Public set to false for co-op, and set a Password only if you want one. Save the file and make sure the server is not running when you edit it. Then open Project Zomboid, go to Host, select the server that uses servertest, start the server, and have your friend join through Join → Steam / Friends. Do not change settings while the server is running and restart the server after any file edit. This setup prevents kicks caused by high ping when hosting co-op from inside the game.
The file is in C/:Users(you user) /zomboid/servers

When you enter a game, it is recommended that you test the mods in singleplayer first and then add them to the server. But there is especially a part in the pause menu during the game that says 'mods.' If you click on it, the ones that are fine will appear in white, and the ones with errors will appear in red.

To determine which mods you can safely use when hosting a Project Zomboid server directly from the game, the first step is to always review the mod’s description on the Steam Workshop. The author usually specifies whether the mod is compatible with multiplayer and with the current game version (such as Build 41 or Build 42). If multiplayer compatibility is not mentioned, the mod may cause issues. It is also strongly recommended to read recent user comments, as players often report crashes, incompatibilities, or conflicts with other mods.

When hosting the server, you must ensure that both the mod and its Workshop ID are enabled in the server configuration. Enabling only one of them will prevent the mod from loading correctly. The load order is also important: large mods (such as maps or major gameplay overhauls) should be loaded first, followed by smaller quality-of-life or item mods. Avoid using multiple mods that modify the same game systems, as this frequently leads to conflicts.

If an error occurs, the game will usually display warning messages when starting the server. For more detailed information, you can check the log file located at
C:\Users\YourUser\Zomboid\Logs\console.txt, where the name of the mod causing the error is often listed. This is the most reliable way to identify problematic mods.

Finally, when testing multiple mods, it is best to enable them in small groups (for example, five at a time). If the server fails to start, you can narrow down the issue to that group and identify the incompatible mod. Following these steps will help you maintain a stable server and avoid most common mod-related issues.

To optimize a Project Zomboid server hosted directly from the game, it is important to start by properly configuring the server settings. Reducing zombie population, lowering the frequency of events such as helicopter encounters and hordes, and disabling unnecessary systems (such as extreme weather or excessive loot) helps reduce server load. It is also recommended to limit the use of heavy mods, especially those that add complex AI, NPCs, advanced health systems, or large map changes, as these significantly impact performance.

Another key factor is the number of players and synchronization range. Keeping a reasonable player count and avoiding overly large or heavily customized maps improves stability. Closing background applications while hosting the server and ensuring sufficient available RAM also has a direct effect on performance.

Finally, keeping the server and mods up to date, removing unused mods, and periodically checking log files for errors helps prevent crashes and long-term performance issues. A clean, well-maintained configuration is usually more stable than an over-modified server.

If you want more guides created by me soon, or even updated in another language, don't hesitate to ask me—I’m happy to help such a wonderful community. That said, have a good survival.