Troubleshooting "Serialization Error Action Needed" in Ready or Not

The "Serialization Error Action Needed" error in Ready or Not, often accompanied by "Corrupt data found, please verify your installation," is a common Unreal Engine issue. Here's how to resolve it:

1. Verify Game Files

   The error message suggests the first step: verify your game files. Ensure Steam isn't in offline mode.

   • Locate Ready or Not in your Steam Library.
   • Right-click, select Properties, then Installed Files, and finally Verify Integrity of Game Files.
   • Steam will check for and re-download any corrupted or missing files. Retry launching the game. If successful, the problem is solved. If not, proceed to the next steps.

2. Disable Mods

   Outdated or incompatible mods, especially those not updated for Unreal Engine 5 (post-July 2024), are a frequent cause. Remove them:

   • In your Steam Library, locate Ready or Not.
   • Left-click Manage, then Browse Local Files.
   • Navigate to ReadyorNot\Content\Paks.
   • Delete the mod.io folder.
   • Launch the game. This will resolve the error but disable all mods.

3. Reinstall Mods (One by One)

   To restore your mods, reinstall them individually to identify any problematic ones.

   • Visit Nexus Mods, Mod.io, or your mod source.
   • Check each mod's last update date. Only reinstall mods updated after July 2024 (UE5 update).
   • Install one mod, test the game. Repeat for each mod. If the error returns, the last installed mod is the culprit; exclude it. Mods not updated for UE5 are incompatible.

4. 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 However, outdated mods are the most common cause of this error.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 on PC.