Why are players kicked with a signature check failed error?

The server is missing the mod's .bikey key, or the server-side mod is not the same version as the players' copy. Copy the mod's key into the server's keys folder and re-download the mod after every Workshop update.

Do players have to install the mods themselves?

No. The DayZ launcher downloads the server's mods automatically when a player joins from the Community tab. Server-only mods passed in -serverMod are not downloaded by players.

In which order should mods go in -mod=?

Dependencies first. Community Framework (@CF) almost always goes first, then the mods that depend on it, then the maps. Mods are separated by semicolons.

Which ID do I use with workshop_download_item?

221100, the Steam ID of the DayZ game, followed by the mod ID (the number in its Workshop page URL). The ID 223350 is the server tool, not the mods.

How to Install DayZ Mods on a Server (Steam Workshop)

TL;DR

A DayZ mod is a folder starting with @, shipped with a .bikey key. To install one: download it from the Steam Workshop (or with workshop_download_item 221100 ID in SteamCMD), copy the @Mod folder to the server root, copy its key into the keys folder, then add it to the launch parameter -mod=@CF;@Mod. Dependencies load first. On a LordHosting DayZ server, everything is uploaded from the panel's file manager.

Mods completely change DayZ: new maps, vehicles, traders, advanced base building and admin tools. Here is how to install them cleanly, without signature errors. If your server is not running yet, start with How to make your own DayZ server.

⚙️ How DayZ mods work

Each mod is a folder starting with @ (for example @CF).
The server loads the mods listed in the -mod launch parameter.
Each mod ships a key (.bikey) that must be copied into the server's keys folder. Without it, players get kicked for invalid signatures.
Players download the server's mods automatically through the DayZ launcher.

⚙️ Step 1: download the mods

Easy way: subscribe to the mods on the DayZ Steam Workshop, then grab their folders from:

C:\Program Files (x86)\Steam\steamapps\common\DayZ\!Workshop\

Server way (SteamCMD): download each mod with its Workshop ID (the number in the mod page URL):

login your_steam_username
workshop_download_item 221100 MOD_ID
quit

221100 is the DayZ game ID. The mod lands in steamapps\workshop\content\221100\MOD_ID.

⚙️ Step 2: copy mods and keys

Copy each @ModName folder to the server root, next to DayZServer_x64.exe.
Open each mod's keys (or key) subfolder and copy the .bikey file into the server's keys folder.

On a Linux server

Use lowercase folder names without spaces (@cf, @vppadmintools) to avoid loading errors: the Linux file system is case-sensitive, and so is DayZ.

On a DayZ server hosted by LordHosting, these two steps are done from the panel's file manager or over SFTP: you upload the mod folder and its key, no command line needed.

⚙️ Step 3: add the mods to the launch line

Edit the launch line:

DayZServer_x64.exe -config=serverDZ.cfg -port=2302 -profiles=profiles -mod=@CF;@VPPAdminTools;@MyMap -dologs -adminlog

Separate mods with semicolons.
Load order matters: dependencies first. Community Framework (@CF) almost always goes first.
Server-only mods (players don't need them) go in -serverMod= instead of -mod=.

⚙️ Step 4: mod config files

Many mods create their config files in the profiles folder on first launch. Start the server once, stop it, then edit them. Some mods also require entries in types.xml or files in the mission folder: always read the mod's Workshop page.

⚙️ Must-have DayZ mods

Mod	What it does
Community Framework (CF)	Base dependency for many mods
VPPAdminTools	Full admin interface (teleport, spawn, player management)
Community Online Tools (COT)	Another popular admin tool
DayZ Expansion	Huge pack: base building, vehicles, market, quests, groups, safe zones
BaseBuildingPlus	More advanced base building
Community maps (Deer Isle, Namalsk...)	New terrain to explore

Start small, test, then add mods gradually. A server with 40 poorly maintained mods crashes often and drives players away.

⚙️ Updating mods

When a mod updates on the Workshop, the server must run the same version as players. Re-download the mod, replace the folder and key, then restart. "Signature check failed" errors almost always mean an outdated mod or key.

⚙️ Ready-to-paste configuration

A start.bat for a server running Community Framework, VPPAdminTools and DayZ Expansion. Folder names must match exactly what sits in the server root.

@echo off
:: Replace: the mod list, in dependency order
set MODS=@CF;@VPPAdminTools;@DayZ-Expansion-Licensed;@DayZ-Expansion-Core;@DayZ-Expansion
:: Server-only mods, not downloaded by players
set SERVERMODS=

:start
start "" /wait DayZServer_x64.exe -config=serverDZ.cfg -port=2302 -profiles=profiles -mod=%MODS% -serverMod=%SERVERMODS% -dologs -adminlog -netlog -freezecheck
timeout 10
goto start

Before launching, check that the server's keys folder holds one .bikey per mod in the list.

✅ Conclusion

Download, copy the folder and the key, add it to -mod= in the right order, restart: the procedure is the same for every mod. Errors almost always come from a missing key or a version that differs from the players' copy. Once your mods are in place, give your server an identity with our guide DayZ PvE, PvP and RP server setup.

On our DayZ servers, you upload your mods from the panel, with enough RAM for big packs like Expansion.

FAQ

The answers to frequently asked questions about DayZ mods are in the FAQ box below. If a question is missing, contact LordHosting support via Discord or by ticket.