How to Fix “Error Code: IS-IN-MF01” in Epic Games

“Epic Games Error Code IS-IN-MF01” appears when the Epic Games Launcher fails to move or relocate essential files during a game’s installation or update process.

This error usually occurs in the final stage of installation, when downloaded files are unpacked and written to the game directory. If the relocation process fails, the launcher halts the operation and displays this error.

In most cases, the issue points to a file-handling or access failure rather than a download problem.

• The target game folder might be corrupted.
• Antivirus software may block certain files.
• The installation directory might lack proper write permissions.

Some users also encounter it after Windows updates or when switching drives (for example, installing games on an external SSD or secondary partition).

Fortunately, this error is entirely software-related and can be resolved by repairing the launcher’s file-access environment.

1. Restart Your PC

Restarting your PC closes all background processes and clears temporary data from memory. This can remove any process that’s locking the installer or preventing file relocation, allowing the launcher to start fresh and complete the installation successfully.

2. Update Epic Games Launcher

An outdated launcher can trigger installation failures due to missing or damaged components. Updating to the latest version replaces outdated files and ensures full compatibility with Epic’s current update framework, which can eliminate the error.

1. Open the Epic Games Launcher.
2. Click your profile icon in the top-right corner.
   
3. Select Settings.
   
4. If an update is available, click Update Now.
   

3. Disable Antivirus Temporarily

Antivirus programs can mistakenly flag the Epic Games installer’s file movement as suspicious activity. Disabling your antivirus temporarily ensures it doesn’t block or quarantine critical files during installation, which can help fix the problem.

1. Search for Virus & threat protection in the Windows search bar and open it.
   
2. Under Virus & threat protection settings, click Manage settings.
   
3. Turn off Real-time protection.
   

Tip: Don’t forget to turn your antivirus back on after completing the installation.

4. Reinstall the Game

If the error persists, it may be due to damaged or missing game files. Uninstalling removes corrupted data that can interfere with the installer, and reinstalling downloads a clean, updated version directly from Epic’s servers. This often resolves file-access or unpacking failures entirely.