How to Fix Ready or Not Serialization Error: Action Needed

If you've ever installed mods for Ready or Not, they should be your firstpoint of investigation. Mods that haven't been updated for Unreal Engine 5 are highly likely to cause this error.

• Open your Steam Library.
• Right-click on Ready or Not.
• Select Manage, then choose Browse Local Files.
• Navigate through the following folders: ReadyOrNot > Content > Paks.
• Locate and delete the mod.io folder. This folder contains all mods installed through the in-game mod browser.
• If you've installed mods manually (e.g., from Nexus Mods), look for any .pak files in the Paks folder that do not have "pakchunk" in their name (e.g., pakchunk0-Windows.pak through pakchunk20-Windows.pak are official game files). Delete any suspicious .pak files.
• After deleting, attempt to launch Ready or Not again and check if the Serialization Error persists.

Steam has a built-in tool that can scan your game installation for missing or corrupted files and automatically redownload them.3 This is a crucialstep if the error message explicitly tells you to verify yourinstallation.

• Go to your Steam Library.
• Right-click on Ready or Not and select Properties.
• Click on the Installed Files tab.
• Select Verify Integrity of Game Files.
• Steam will now scan your game files. This process may take several minutes.If any files are found to be corrupted or missing, Steam will redownload them.
• Once the verification is complete, start the game to see if the problem is fixed.

If you're determined to play with mods, you can try reinstalling them, but do so with extreme caution.

• Go to the website or platform where you originally obtained your mods (e.g., Nexus Mods, mod.io).
• Only reinstall mods that explicitly state they were updated after July 2024 (the approximate time Ready or Not switched to Unreal Engine 5). Older mods are highly unlikely to work.
• Install mods one at a time. After installing each mod, launch Ready or Not to check if the Serialization Error reappears.
• If the error appears after installing a specific mod, that mod is theproblem. Delete it and avoid using it until its creator releases anupdated, compatible version.

If none of the above solutions work, a complete uninstall and reinstall of the game is often the last resort, but also the most effective atensuring a clean slate.

• Before uninstalling, manually delete any remaining mod files as described in step 1, especially the mod.io folder and any custom .pak files. This ensures that a fresh installation isn't immediately corrupted by lingering mod data.
• Open your Steam Library.
• Right-click on Ready or Not.
• Select Manage, then choose Uninstall.
• Follow the prompts to uninstall the game.
• Once uninstalled, restart your computer.
• Reinstall Ready or Not through Steam. This will download a fresh, error-free copy of the game.