Home >  News >  Ready or Not: Fixing 'Serialization Error'

Ready or Not: Fixing 'Serialization Error'

by Natalie Mar 13,2025

Ready or Not, while sounding deceptively innocent, is a hardcore SWAT-style FPS that delivers intense single and multiplayer action. However, even the most seasoned tactical operators can run into technical snags. Here's how to resolve the dreaded "Serialization Error Action Needed" in Ready or Not.

Tackling the "Serialization Error Action Needed" in Ready or Not

Screenshot showing the error message in Ready or Not
Screenshot via The Escapist

The "Serialization Error Action Needed" error, often accompanied by "Corrupt data found, please verify your installation," is a common Unreal Engine issue. Let's explore the solutions:

1. Verify Your Game Files

The game itself suggests the first step: verifying your installation. Ensure Steam isn't in offline mode.

  1. Open your Steam Library and locate Ready or Not.
  2. Right-click, select "Properties," then "Local Files."
  3. Click "Verify Integrity of Game Files."

Steam will scan and automatically replace any missing or corrupted files. Try launching Ready or Not again. If successful, problem solved! If not, proceed to the next step.

2. Remove Mods

Outdated or incompatible mods, especially those not updated for Unreal Engine 5, are a frequent culprit. To remove mods:

  1. Open your Steam Library, locate Ready or Not, and click "Manage," then "Browse Local Files."
  2. Navigate to the ReadyOrNot > Content > Paks folder.
  3. Delete the mod.io folder.

This will resolve the error, but you'll lose your mods temporarily. Follow the next step to restore them.

3. Reinstall Mods (Selectively)

Reinstall your mods one by one, checking their update dates. Visit Nexus Mods, Mod.io, or your preferred mod source.

Crucial: Only reinstall mods updated after July 2024 (when Ready or Not transitioned to UE5). Older mods are likely incompatible. Install a mod, test the game, and repeat. If the error returns, the last installed mod is the problem; skip it.

Last Resort: Reinstall Ready or Not

If all else fails, a clean reinstall of Ready or Not might be necessary. While less likely, hard drive corruption could also be a factor. However, outdated mods are the most common cause of this error.

Ready or Not is available now for PC.