Mods & Workshop

How to Install Maps & Mods Manually in Killing Floor

While Steam Workshop exists, it is buggy in KF1. Many classic maps come as .zip or .rar archives that you must install manually.

KF-WestLondon KF-WestLondon, the most iconic Killing Floor map.

File Extensions Explained

Killing Floor uses the Unreal Engine file structure. Each file type goes into a specific folder inside KillingFloor.

  • .rom (Maps) -> KillingFloor/Maps
  • .utx (Textures) -> KillingFloor/Textures
  • .ukx (Animations) -> KillingFloor/Animations
  • .usx (Static Meshes) -> KillingFloor/StaticMeshes
  • .u / .ucl (Code/System) -> KillingFloor/System
  • .ogg / .uax (Sounds) -> KillingFloor/Sounds (or Music)

Installation Steps

  1. Download the map/mod archive.
  2. Extract it. Most archives already have the folder structure (Maps, System, etc.).
  3. Copy the folders.
  4. Paste them into your game root folder: Steam\steamapps\common\KillingFloor\.
  5. Merge folders when asked.
    • Note: Never overwrite "System" files unless you are sure. Overwriting core game files can break your game.

Common Errors

"Package 'TextureName' Version Mismatch"

This means the server has a different version of the file than you. Fix: Go to the folder containing that file (e.g., Textures) and delete the problematic file. When you rejoin the server, the game will download the correct version automatically.

Map not showing in list

If you put a .rom file in Maps but can't see it:

  1. Check the "Map Name" filter in the menu.
  2. Ensure the file name doesn't have spaces or weird characters.

Additions

KFMapAnalyzer 1.0 (SiriusHARD, requires .NET Framework 4.5) shows which resources from your client a chosen map uses. Put the exe into the client or server root, where the Maps, Animations, Sounds and other folders are. The "Save Report" button saves the package list to a text file named mapname.rom.txt next to the program. It only checks the map against the resources in your client's Animations, Sounds, StaticMeshes and Textures folders: if you lack a package, it will not find it. UE Explorer was named in the same thread as an alternative.