Ultimate Multiplayer Guide [b41]

I will tell you how to go all the way from buying the game to meeting other players online

Introduction

Have you bought the game on Steam and want to play Multiplayer with friends or random players? Then this guide is for you. I will tell you how to go all the way from buying the game to meeting other players online.

IMPORTANT: Before you read this guide make sure you DO NOT have any mods!

[QnA] Mod Helper - build 41 MP

If you are still struggling with getting your server work after going through this guide, check this guides:
[QnA] Admin Helper - build 41 MP
[QnA] Client Helper - build 41 MP

For request help in the comment section below answering the following questions:
• What is your game version?
• Are you using the "Host" function or is it a dedicated server?
• Do you have any mods enabled?
• What is the exact Error (can be a screenshot)
• Share the Console txt file.
(Go to C:\Users\YourUserName\Zomboid > Open the console.txt > Copy everything from there to https://pastebin.com/ > Click “Create a new paste” > Share the website link of the new paste here)

You want to play on server

Installation
1. Open your Steam Library and find Project Zomboid in the list.
2. RMC (Right mouse click) the game, and open Properties.
3. Choose NONE (none is the latest stable build of the game)
4. Install (or update) the game.
5. Start the game.

Multiplayer options:

• "Host" server - You can run a coop game. To join an existing one, you have to be invited by a Steam friend.
  
• "Dedicated" server - Search in the "Internet" tab by its server name, or connect directly by using the server IP.

Filling the description.

• Server name: Server name.
  
• IP: Server IP if you are joining by one.
  
• Local IP: Skip here.
  
• Port: 16261 (This is the default Project Zomboid port)
  
• Server password: Server password (Use if the server has one)
  
• Description: Write or use the server description when adding to your Favorites.
  
• Account Username: Write the nickname that you want to have on the server.
  
• Account Password: Write your password that you will use for the server here.

How to find a public server:
Main menu > Join > Click the "Internet" tab and choose server you like. Or you can find region-based servers and coop servers in our Discord. TIS Discord[discord.gg] in LFG chats!

7. Have fun!
- If you have issues with connect to server or problems with game - check this guide:
[QnA] Client Helper - build 41 MP

How to run a "Host" server.

1. Start the game
2. Main menu > Host
3. Manage settings > Create new settings > Tune your server > Save
4. Back > Start
5. To invite your friends: ESC > Invite. Or invite them via Steam
6. How to make yourself an admin: /setaccesslevel "username" admin
Where username is your in-game name (with space and capitalized letters if you have those) and with ".

Server Memory Advice:
For a bare minimum, have 2Gb set as your memory for the server, for a better experience have at least 2Gb, additionally, add ~500Mb per any planned player that will be on the server.
-- Example: 4Gb for 4 players (2Gb Starting + 4*500mb = 4Gb) --

Remember!
Running a server is pretty demanding. You need an SSD drive, a stable internet connection, enough RAM for the server and your PC and players from your region !!!

Other:
- If you have issues with host server (for example Friends can't connect to server) - check this guide: [QnA] Admin Helper - build 41 MP
- For admin tools read this: Admin tools - build 41 MP

How to create a Steam dedicated server (on your PC)

If you want to host dedicated server on your PC, you will need to solve the following problems:
1. You need a public IP address for your PC, make sure your internet service provider has allocated one for you.
You can simply call your provider and ask if you have one.

How to Find Your Private and Public IP Addresses[www.howtogeek.com]
!!! Your private and public IP must be same
-- You do not need a public IP address to host a coop "Host" server.

2. You need to open these ports:
UDP: 16261 and 16262

2.1. Open ports in windows firewall

2.2. Open ports in your antivirus: (skip if you don't have antivirus on your PC)
Check how to open ports in antivirus in Google
(Example Google Search: "Antivirus open ports")
A note: Some aggressive AV programs ignore the exceptions, and removing AV can be only way to have your server run.

2.3 Open ports in your router: (skip if you have direct connect)
You can find guides on how to open the ports on your specific router by simply looking up the router name and writing "port opening" after it.
Example Google Search: "Asus router port opening"

Otherwise - Other players will not be able to see and connect to your server!

---

STEPS:
1) Go to your Steam Library > On the top left, click the "Games" menu and check "Tools" to allow game tools to show up in your Steam Library
2) Find the “Project Zomboid Dedicated Server” in your Steam Library
3) Rightclick the Dedicated Server Tool > Properties > Betas > NONE to update the server to the latest MP version (If needed).

You will now have two new folders:
The main server files are located by default here
"SteamLibrary\steamapps\common\Project Zomboid Dedicated Server"
The server settings are located here
"C:\Users\YourPCUserName\Zomboid\Server\servertest.ini"

4) Go to the servertest.ini and tune your settings.
Guide: Configure server - build 41 MP
5) Configure amount of RAM for you server
- Go to your "SteamLibrary\SteamApps\common\Project Zomboid Dedicated Server" folder
- Open StartServer64.bat in text editor
- Change next parameters:
Delete the -Xms16g parameter
Change the -Xmx to however much RAM you need for your server (Example: -Xmx6G)
Recommend amount of RAM: 2Gb as a start + 500Mb per player
So if you want play in team of 10 players, need (2 + 0.5*10)=7Gb of RAM
- Save and close this file.
5) Run the StartServer64.bat file
6) Wait until you see the successful "*** SERVER STARTED ****" message
DON'T CLOSE CONSOLE
7) Start your game > Click Join > Fill your server info on the right side of the screen
8) Click "Save" and now you can join your server from your "Favorites" tab.
9) HAVE FUN, DON'T GET BITTEN!

Note: Launching a server will open a command console window that begins executing the server on your machine. On the first run, it will prompt you to set a password for the admin account it will create. Don't lose the password you create !!!

How to configure a dedicated 'rented' server (or VPS) (Windows)

How to configure a dedicated 'rented' server (or VPS) (Windows server 2019)

How to configure a dedicated 'rented' server (Linux)

How to configure a dedicated 'rented' server (or VPS) (Ubuntu)

How to configure a dedicated 'rented' server (or VPS) (Debian 11)

[KDTenshi]

I'm trying to host a server using the ingame "Host" button and when my friend is connecting to me he gets an error that port 16262 is closed on server and it results in high ping, sometimes he even gets kicked from the server. I've tried opening ports on my router and Windows Firewall but it didn't help. Can you please tell me what can i do to fix this?

[Doktor]

This is very helpful, but do you know what to do when (as a host) your server just won't allow you to join? It loads as usual, my friends are able to join the server, but I, as a host, only see this writing that says "server launched - access denied". I would be really grateful if anyone knows how to fix this. Thanks in advance!

[EagleEye8045]

I created this tool that will automatically grab all the mod and workshop ids from a collection. It should help speed up the process rather than having to do it manually https://pzidgrabber.com/ .

[bigcheezyboss]

@Funkycord1336 I had the same issue. For me it ended up being because I ran out of storage space. If you're on linux you can check with `df /` and `Use%` will show you how much space you're using.

[Funkycord1336]

everything was working fine until i tried starting the dedicated server and i kept getting this error any reason why ?

src\tier0\threadtools.cpp (3645) : Assertion Failed: Illegal termination of worker thread 'CFileWriterThread'
src\tier0\threadtools.cpp (3645) : Assertion Failed: Illegal termination of worker thread 'CFileWriterThread'
src\tier0\threadtools.cpp (3645) : Assertion Failed: Illegal termination of worker thread 'Thread(0x00007FFBBEBBAE50/0x000'
src\tier0\threadtools.cpp (3645) : Assertion Failed: Illegal termination of worker thread 'Thread(0x00007FFBBEBBAE50/0x000'
src\tier1\fileio.cpp (5528) : CFileWriterThread already exited
src\tier1\fileio.cpp (5528) : CFileWriterThread already exited
src\tier1\fileio.cpp (5528) : CFileWriterThread already exited
src\tier1\fileio.cpp (5528) : CFileWriterThread already exited
src\tier1\fileio.cpp (5528) : CFileWriterThread already exited
src\tier1\fileio.cpp (5528) : CFileWriterThread already exited

[dgeronimo791]

i have problem, when i start the server, i have error when i press button invite friends
ERROR: General , 1688895322227> 0> ExceptionLogger.logException> Exception thrown java.lang.reflect.InvocationTargetException at NativeMethodAccessorImpl.invoke0 (Native Method).
ERROR: General , 1688895322227> 0> DebugLogStream.printException> Stack trace:
java.lang.reflect.InvocationTargetException

[Lvl3Mage]

@kaputzz Had the same issue, tried almost everything and nothing worked. What ended up solving it was re downloading the server using SteamCMD.

[kaputzz bandit.camp]

can someone add me on discord, to help me out?
Here's the discord id to add: kaputzz#6463

[kaputzz bandit.camp]

Hello gentleman,

I really need help setting up a Steam dedicated server.
I can see the server on the favorites list, after i directly add the info but not in the internet tab, if i search for it.
Also can't connect to it (at least locally it just says "getting server info" and doesn't do anything) when i press 'join server'

[Zudakas]

@kroh I would double check your server's LAN ip, to make sure the new NIC didn't get a different IP from your router. New NIC means a new MAC address, so it probably changed the ip.