Docs / Docs

Troubleshooting

Solutions to the most common problems with Modrex and PAYDAY 3 mods.

Mods not loading in-game

Most common cause: missing -fileopenlog launch argument.

Add -fileopenlog to Settings - Launch Options. Without it, Unreal Engine 5 does not scan the ~mods/ directory and no mods will load regardless of what’s installed.

Other things to check:

• The mod’s toggle is on (not disabled).
• A higher-priority mod isn’t overriding it - try moving it lower in the list.
• The mod targets your version of PAYDAY 3.

Game not detected on first launch

If Modrex can’t find PAYDAY 3 automatically:

1. Go to Settings - Game Path and click Browse.
2. Navigate to the folder that contains PAYDAY3/Content/.
3. Click Select Folder - Modrex validates and saves the path.

On Xbox Game Pass, Modrex scans drive roots (C: through G:) for the Xbox install path. This can take a few seconds on the first detection pass.

”Missing file” badge on a mod

This appears when Modrex’s state file references a .pak that no longer exists on disk. This happens after manually deleting files or moving your game folder.

Either Reinstall the mod to re-download it, or right-click and select Uninstall to remove the stale entry.

Modrex won’t launch after a Windows update

Xbox Game Pass installs can lose their file permissions after major Windows updates. Run Modrex as administrator once to restore access, then relaunch normally.

Log file location

When reporting a bug, always attach the Modrex log file:

Windows   %APPDATA%\Modrex\logs\modrex.log
Linux     ~/.config/modrex/logs/modrex.log

Open it directly from Settings - Open log file.