Zombies do not harm the character. | Project Zomboid | Page 1

dawn trout Jan 11, 2026, 5:54 PM

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I’m experiencing a server-side issue where single zombies do not deal damage to the player character when biting. The server logs show errors like the following:

ERROR: General f:3772, t:1768152530616, st:97,862,858> GameServer.mainLoopDealWithNetData > Error with packet of type: ZombieHitPlayer for 396316788204620756
ERROR: General f:3772, t:1768152530616, st:97,862,858> GameServer.mainLoopDealWithNetData> Exception thrown
java.lang.NullPointerException: Cannot invoke "zombie.characters.IsoPlayer.getUsername()" because the return value of "zombie.characters.IsoGameCharacter.getOwnerPlayer()" is null
at ZombieHitPlayerPacket.log(ZombieHitPlayerPacket.java:82)
Stack trace:
zombie.network.packets.hit.ZombieHitPlayerPacket.log(ZombieHitPlayerPacket.java:82)
zombie.network.packets.hit.HitCharacter.processServer(HitCharacter.java:31)
zombie.network.PacketTypes$PacketType.onServerPacket(PacketTypes.java:943)
zombie.network.GameServer.mainLoopDealWithNetData(GameServer.java:1593)
zombie.network.GameServer.main(GameServer.java:897)

If the player gets surrounded by a large group of zombies, they die almost instantly.
However, if a new character is created afterward, the screen turns black, and only reconnecting to the server helps.

After reconnecting, the character that was supposedly killed by zombies turns out to be alive and completely unharmed.

Server setup:

Dedicated server launched via SteamCMD

OS: Debian 13

Game version: Build 42.13.1

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Installed mods:

damnlib;
twistvbugfix;
88toyotaHilux;
89defender;
92amgeneralM998;
92amgeneralM998extra;
92fordCVPI;
93fordF350;
98stagea;
BetterGeneratorInfo;
ChuckleberryFinnAlertSystem;
DRAW_ON_MAP;
Disable42panel;
KI5trailers;
LWBetterElectronics;
MoreDamagedObjects;
PZUkrainianOverhaul;
StarlitLibrary;
RepairableWindows;
errorMagnifier;
SkillRecoveryJournal;
TraitsPurchaseSystem;
newbie_loot_refill_b42;
VehicleRepairOverhaul;
VehicleSalvageOverhaulB42;
better-auto-mechanics;
EventTracker

hot pebbleBOT Jan 11, 2026, 6:30 PM

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If you have issues with mods, try disabling them one by one or in batches to figure out which specific mod is causing the problems.
Do it on a new save to to prevent any issues on your current playthrough as removing mods can cause items to be permanently deleted.
After you find out which mod is problematic, consider reporting the problem to the mod creator on their workshop page.

dawn trout Jan 11, 2026, 6:42 PM

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The issue occurs even on a completely vanilla server.
I suspect the world was created or initialized incorrectly.
Reporting this so developers can investigate and advise how to fix or prevent this, and to document it as a bug.

pulsar iris Jan 11, 2026, 10:22 PM

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Does it happen even if the world is created without mods?

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Since removing mods from a world that was created with them cannot be accepted as a bug

dawn trout Jan 12, 2026, 10:29 AM

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<@&756556556488933526>
I’ll try to explain everything clearly and in order.

When multiplayer for build 42 was released on December 11, I launched the server. It worked until the fix 42.13.1 came out.
After the fix was released, I deleted all saves related to the world and updated the server (not a clean reinstall) via SteamCMD to version 42.13.1, then launched a completely new world. The server was started without any mods.

At that time, I didn’t know about the issue. I was informed about the problem only after I had installed several mods. At first, I thought the problem was caused by the mods, so I tried running separate test servers without them. Later, I also launched servers with the same set of mods, and the problem did not occur there.

I came to the conclusion that most likely, when I updated my server from the unstable build 42 to 42.13.1, something didn’t update properly, and when the world was generated on 42.13.1, something went wrong.

There are about 10 active players on my server, and I really wouldn’t want to wipe the world, so I’m reaching out to you in the hope that there might be a solution to this problem.

(I was thinking that maybe it’s necessary to overwrite some files from the Saves folder, but I don’t know which ones—similar to how it’s done when reloading the map in already generated worlds.)

pulsar iris Jan 12, 2026, 11:31 AM

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Hm, I understand, did those test servers use the exact same server files or did you install the server files from SteamCMD again for those tests?

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And how about server settings? Did they use the exact same settings or just the default values

dawn trout Jan 12, 2026, 12:22 PM

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@pulsar iris Yes, the server was installed via SteamCMD in parallel with my “production” server.

At first, I launched a vanilla server with the default settings that the game provides when starting a server via ./start-server.sh, without using a configuration file, so the server generated all the settings by itself.
Everything worked perfectly on it.

After that, I copied all the configuration files from the Server directory of my production server to the test server and launched a new world with mods and with the same settings that are used on my production server, and everything was also perfect.

So now I’m scratching my head, trying to figure out what could be causing the issue.

pulsar iris Jan 12, 2026, 12:52 PM

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dawn trout <@164105079534780418> Yes, the server was installed via SteamCMD in parallel wit...

It may be an install issue on the production server, might be worth wiping the server install files and then do a reinstall?

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Your save data would be kept this way

dawn trout Jan 12, 2026, 2:15 PM

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I tried that as well. I moved the world save and the configuration files to a neighboring virtual machine (my servers are running on Proxmox), where I set everything up on a completely clean server installation, but it didn’t help.

pulsar iris Jan 12, 2026, 3:11 PM

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Hm, that is pretty bad, would mean the save itself isnt right

pulsar iris Jan 12, 2026, 3:12 PM

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dawn trout The issue occurs even on a completely vanilla server. I suspect the world was cr...

How did you test this vanilla server though? SInce you mentioned the issues do not happen on any test servers

dawn trout Jan 12, 2026, 4:46 PM

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@pulsar iris I started the server without mods and without any additional settings in the files:
servertest.ini
servertest_SandboxVars.lua

It was simply a clean launch of a new world via the command line using start-server.sh.

All settings were generated automatically by the server itself, after which I conducted testing.

pulsar iris Jan 12, 2026, 6:48 PM

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dawn trout <@164105079534780418> I started the server without mods and without any addition...

This was on the production server or a secondary server?

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Also, why not delete those files? Were those generated by any other servers?

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Since you mentioned you didnt modify them

dawn trout Jan 12, 2026, 6:55 PM

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@pulsar iris All tests were conducted on a test server. I don’t touch production — people are playing there.

Each server start was clean, regardless of whether mods had been installed on the server before or not. That is, I deleted all saved data and then launched the server.

(I do have one idea about what might be causing this; I’m currently investigating it.)

pulsar iris Jan 12, 2026, 7:02 PM

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Hm, let me know if you have any specific reproduction steps, since I launched 3 servers in B42 myself and they all work perfectly fine out of the box

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Some have default settings, some modified

dawn trout Jan 13, 2026, 3:14 PM

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@pulsar iris I investigated the problem.

The issue starts to show itself when there are more than two people on the server. Specifically, damage stops registering on characters, and zombies periodically disappear and teleport. I tried to rule out all purely technical issues. In particular, I checked the internet connection, verified the physical side of the connection such as cables, and checked the load on the internet channel (I have a fiber-optic connection with gigabit speed). I also checked whether all the required ports are properly forwarded.

After that, I started disabling various settings directly on the game server that I initially thought might be overloading the channel and causing the issues.

In general, to summarize: if I’m alone on the server or there is just one additional player, everything is fine. If there are more players, problems begin. This happens on modded servers.

This evening I will deploy a vanilla test server and invite five players there for testing. After I get some information, I will describe it here.

pulsar iris Jan 13, 2026, 3:22 PM

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Thanks for the info, there are currently quite a few of 42 servers with several players running, though you are the first one to report this issue, so I assume it has to be something mod related then at the very least, or something with your specific config

dawn trout Jan 14, 2026, 3:03 PM

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@pulsar iris
Hi. I tested a ton of parameters and different combinations (honestly, more than I ever test at work 😅), and in the end I found what the issue was.

It turned out to be caused by one small and barely noticeable parameter:

SwitchZombiesOwnershipEachUpdate, which was set to true.

As I understand it, this parameter binds a specific zombie to a specific player, and only the linked pair (zombie + player) can properly deal/receive damage. Other players end up not receiving damage from that zombie because
zombie.characters.IsoGameCharacter.getOwnerPlayer() returns null.

This also causes teleporting issues with zombies that are not properly linked. The problem affects zombies that were already spawned while this setting was enabled as well. Even if you later disable the parameter, those zombies continue to behave incorrectly, and only newly spawned zombies start behaving normally again.

In my opinion, this is a very questionable parameter. I honestly don’t fully understand why it exists at all, and as far as I remember, it did not exist in build 41.

I also have a question: where is the best place to report this issue? Is there an official channel for reporting it, or can it be forwarded through you somehow?

pulsar iris Jan 14, 2026, 3:41 PM

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dawn trout <@164105079534780418> Hi. I tested a ton of parameters and different combinatio...

Was that parameter set to its default value or did you change it when configuring the server?

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The best place would be our bug reports forum, our testers go through all the posts there
https://theindiestone.com/forums/index.php?/topic/43261-read-here-first-bug-reporting-guideformatting

The Indie Stone Forums

Bug Report Guide [Updated 18/12/2025]

If the game is crashing, please use the SUPPORT section of the forum and provide this information in your post. Linux/Mac Logs Location: Home\Zomboid\Logs.zip Windows Logs Location: Users\YOURNAME\Zomboid\Logs.zip The Indie Stone’s Bug Report Guide Mods must be disabled. Reports with mods will no...

dawn trout Jan 14, 2026, 4:52 PM

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pulsar iris Was that parameter set to its default value or did you change it when configurin...

No, this parameter was disabled by default.

dawn trout Jan 14, 2026, 11:26 PM

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@pulsar iris
I have one more question.
In Build 41, if an area was claimed/private, it was not possible to enter vehicles located there.

In Build 42, this functionality is no longer present — anyone can enter, break into a vehicle on private territory, and drive away.
Could you please tell me whether there is a corresponding setting in the server options, or if this feature was removed from the game entirely?

pulsar iris Jan 15, 2026, 10:07 AM

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dawn trout <@164105079534780418> I have one more question. In Build 41, if an area was cla...

SafehouseAllowTrepass=false```

Should be this setting

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In B41, if you had vehicles on the edges of the safehouse, players could sometimes enter through the door at the edge, or If I remember correctly, they couldm drive another vehicle inside and push the vehicle out

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Most people build garages after that

#Zombies do not harm the character.