Home News "Fix 'Serialization Error' in Ready or Not: Quick Guide"

"Fix 'Serialization Error' in Ready or Not: Quick Guide"

by Emery May 03,2025

*Ready or Not* might sound like a kid's game, but it's far from it. This intense SWAT-themed FPS offers both single and multiplayer experiences, though you might encounter some technical hiccups along the way. Here's a comprehensive guide on how to resolve the "Serialization Error Action Needed" in *Ready or Not*.

How to Tackle 'Serialization Error Action Needed' in Ready or Not

Photos of the Soft Objects for 23 Megabytes A Second in Ready or Not as part of an article about how to fix the 'Serialization Error Action Needed'Screenshot via The Escapist

The *Ready or Not* error "Serialization Error Action Needed" often comes with the message "Corrupt data found, please verify your installation." This is an Unreal Engine error, and there are several steps you can take to address it.

1. Verify Your Installation

The first step is to follow the prompt and verify your installation. Here's how to do it in Steam, ensuring you're not in offline mode:

  • Go to your Steam Library and locate *Ready or Not*.
  • Right-click on the game and select "Properties."
  • Navigate to "Installed Files" and click on "Verify Integrity of Game Files."
  • This process will check for any missing or damaged files and re-download them if necessary.
  • After the verification, try running *Ready or Not* again. If the issue is resolved, great! If not, you may need to take further action.

2. Remove Any Mods

The "Serialization Error Action Needed" can also be triggered by outdated or broken mods, especially those not updated for Unreal Engine 5. Here's how to remove them (via CosmoCart):

  • In your Steam Library, find *Ready or Not* and left-click on "Manage," then "Browse Local Files."
  • Open the "ReadyorNot" folder, then the "Content" folder, and finally the "Paks" folder.
  • Delete the "mod.io" folder by left-clicking and hitting the delete key or right-clicking and selecting "delete."
  • Try running the game again. Without mods, it should work, but you'll need to reinstall them if you want to use them.

Related: Ready or Not: What's Better, DirectX 11 or DirectX 12 (DX11 vs. DX12)?

3. Reinstall Your Mods

To get your mods back, reinstall them one at a time. Visit Nexus Mods, Mod.io, or your mod source and check the update date for each mod:

  • If a mod was updated after July 2024, when *Ready or Not* transitioned to UE5, it's safe to install.
  • If not, avoid installing it as it won't be compatible with the UE5 version of the game.
  • Install a mod, launch the game, and see if the error reappears. If it does, the last mod you installed is likely the culprit and should be skipped.

If all else fails, consider uninstalling and reinstalling *Ready or Not* from scratch. While hard disk corruption is a possibility, most instances of this error are linked to outdated mods. This guide should help you fix the "Serialization Error Action Needed" in *Ready or Not*.

*Ready or Not is available now for PC.*

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