Installation

Download & install

Grab the latest release from the download page or directly from GitHub Releases.

Windows

Run the modrex_x86_64.exe installer and follow the prompts. Modrex checks for updates on every launch and can install them in-app - you won’t need to manually reinstall for future versions.

Linux

The quickest way is the install script - it installs the right package through apt, dnf, or zypper (so updates flow through your package manager), and falls back to a self-contained AppImage on other distributions:

curl -fsSL https://modrex.net/install.sh | sh

Or pick the package for your distribution manually:

• .deb - Debian, Ubuntu, and derivatives. Install with sudo dpkg -i modrex_x86_64.deb.
• .rpm - Fedora, RHEL, and derivatives. Install with sudo rpm -i modrex_x86_64.rpm.
• .AppImage - Any distribution. Mark the file executable (chmod +x modrex_x86_64.AppImage) and run it directly.

Choose a game

On first launch Modrex asks which game you want to manage. Supported games:

• PAYDAY 3 - .pak mods in the Unreal ~mods folder.
• PAYDAY 2 - BLT/BeardLib mods and mod_overrides content.
• PAYDAY: The Heist - PDTH BLT/DAHM mods and mod_overrides content.
• Crime Boss: Rockay City - official ModKit folders, legacy .pak mods, and UE4SS mods.

You can switch games from the sidebar at any time. Each game keeps its own path, launcher, launch options, installed list, and folders.

Use the search box in the game picker to filter by name, or enable the Installed only toggle to show only games you have set up.

See Supported games for launcher support, install targets, loader notes, and priority behavior per game.

For the shared model behind game switching and target routing, see Games and targets.

Game detection

Modrex automatically scans for the selected game across the launchers it supports. If it finds your install, you’re ready to go.

If detection fails, set the path manually:

1. Open Settings from the bottom of the sidebar.
2. Under Game Path, click Browse and select the game’s root folder.
3. Modrex validates the path and identifies your launcher.

Select the root folder, not the mods folder. On Steam this is typically SteamLibrary/steamapps/common/<game name>.

Launch options

For most PAYDAY 3 .pak mods to work, the game needs the -fileopenlog launch argument. Add it in Settings - Launch Options, or directly in your launcher’s launch arguments for PAYDAY 3.

-fileopenlog is a PAYDAY 3 requirement. Other supported games use game-specific loader or install-target behavior instead.

Requirements

Game	Steam	Epic Games	Xbox App
PAYDAY 3
PAYDAY 2
PAYDAY: The Heist
Crime Boss: Rockay City