How to Fix the Serialization Error in Ready or Not (2025): Causes and Easy Fixes

If you’re trying to enjoy the intense tactical gameplay of Ready or Not, running into the Serialization Error: Action Needed can feel like a total buzzkill. Usually paired with the message “Corrupt data found, please verify your installation”, this issue has been plaguing players—especially those using mods or jumping back in after a major update.

Also Check: Ready or Not Console Release Time and Crossplay Support Revealed

But don’t worry. Whether you're running Unreal Engine 5-compatible mods or none at all, there are a few ways to fix the problem and get back into the action.

What Causes the Serialization Error in Ready or Not?

This error typically points to damaged or incompatible game files, and there are two common culprits:

• Outdated mods that haven’t been updated for the current version of the game.
• Corrupt game files after an update or install error.

Ever since Ready or Not transitioned to Unreal Engine 5 in July 2024, many older mods became unstable or completely incompatible, leading to issues like this.

How to Fix the Serialization Error in Ready or Not

Here are a few methods that can help resolve the issue:

1. Remove Outdated Mods

Mods are often the source of the problem—especially if they haven't been updated since the Unreal Engine 5 switch.

Here’s how to remove them:

1. Open your Steam Library.

2. Right-click on Ready or Not, then select Manage > Browse Local Files.

3. Navigate to:
   ReadyOrNot > Content > Paks

4. Locate and delete the mod.io folder.

This will uninstall all mods from the game. Try launching Ready or Not again to check if the error still appears.

2. Verify Integrity of Game Files

If the error message suggests verifying your installation, this should be your next step. Steam can check and fix any corrupted or missing files.

Steps:

1. Go to your Steam Library.

2. Right-click Ready or Not > Properties.

3. Click the Installed Files tab.

4. Select Verify Integrity of Game Files.

Steam will now scan your installation and automatically re-download any broken files. Relaunch the game afterward.

3. Reinstall Only Updated Mods

Still want to use mods? Here's how to do it the right way:

• Download only mods that were updated after July 2024 (post-Unreal Engine 5 update).
• Install them one at a time and launch the game after each install.
• If the Serialization Error appears again, remove the last mod you installed—it’s likely the culprit.

This method helps isolate problematic mods and keep your game running clean.

4. Do a Clean Reinstall

If nothing else works, a full reinstall may be necessary.

Steps:

1. Uninstall Ready or Not from your system.

2. Delete any leftover files in the game directory (especially in the Paks folder).

3. Reinstall the game fresh from Steam.

This ensures you're starting from a clean slate with no broken files or conflicting mods.

The Serialization Error may look serious, but in most cases, it’s a fixable issue. Here’s how you can avoid running into it again:

• Avoid outdated mods.
• Always verify mod compatibility with Unreal Engine 5.
• Use Steam’s file verification tool regularly after updates.
• Keep your game and mod sources clean and trustworthy.

With the right steps, you'll be back to breaching doors and clearing rooms in no time.