Thunderstore has become an essential tool for modding communities across multiple games, including BONELAB, a VR sandbox game from Stress Level Zero. Recently, some users have encountered a frustrating issue: the error message “Failed to Load CP2ILL” when trying to launch BONELAB with mods enabled. This problem can halt gameplay and prevent access to a custom-modded experience that players have grown to love.

TL;DR

If you’re encountering the “Failed to Load CP2ILL” error in BONELAB via Thunderstore, it’s usually due to a corrupt or outdated mod, incorrect mod load order, or mismatched game/mod versions. To resolve the issue, check for updates in Thunderstore, verify file integrity, disable problematic mods, and ensure mod managers are synchronized. Reinstalling mod components or Thunderstore itself may also help.

Understanding the CP2ILL Error

Before diving into fixes, it’s important to understand what you’re dealing with. CP2ILL is not a commonly documented system file or standalone mod; it’s almost certainly a mod dependency or component that another major mod requires to function. When the game launcher, via Thunderstore, fails to load this component, the error throws off the whole mod load process.

This typically occurs due to one or more of the following:

  • Corrupted or missing mod files
  • Dependencies not being installed correctly
  • Incompatibility between mod versions and the current BONELAB game build
  • Mod manager not updating or syncing with the game properly

Step-by-Step Fix Guide

1. Update Thunderstore Mod Manager

This should be your first course of action. Thunderstore updates frequently to stay compatible with the latest game builds and mods. If it’s outdated, it may try loading mods that no longer function correctly.

  1. Launch Thunderstore Mod Manager.
  2. Check for updates via the gear/settings icon.
  3. Allow any updates to install and relaunch the app.

2. Verify BONELAB Game Files

Sometimes a corrupted core file will prevent any mods, including dependencies like CP2ILL, from loading correctly.

Steps for Steam:

  1. Go to your Steam Library.
  2. Right-click on BONELAB and select Properties.
  3. Under the Local Files tab, click Verify Integrity of Game Files.

This should automatically replace any missing or error-prone files within the BONELAB directory.

3. Identify the Mod That Requires CP2ILL

Because CP2ILL isn’t a well-documented standalone mod, it may be a dependency used by another mod on Thunderstore.

  • Go through your mod list one by one; disable them using Thunderstore’s toggles.
  • Launch BONELAB after turning off each mod until you stop seeing the error.
  • Once identified, verify if the problematic mod requires a dependency called CP2ILL or something similar. Reinstall both it and its dependencies.

4. Re-download the CP2ILL Component

If you’ve zeroed in on the mod using CP2ILL, the next step is to manually reinstall it:

  1. Open Thunderstore and locate the mod.
  2. Check the mod description for any required dependencies — CP2ILL or similar.
  3. Click Install with Dependencies to ensure everything is downloaded properly.
  4. Verify that all items show as Enabled before launching BONELAB.

5. Sync Thunderstore Profiles

If you’re using multiple profile setups in Thunderstore (such as vanilla vs modded profiles), ensure that the profile you are trying to launch is fully synced and uses the active BONELAB installation.

  1. Select your current profile from the dropdown list in Thunderstore.
  2. Click on the sync button or check if mods are being loaded into the correct BONELAB directory.

6. Clear Cache and Rebuild Load Order

Sometimes old configuration data can cause these ambiguous errors.

  • Navigate to your Thunderstore cache folder (defaults vary by OS, but typically found in AppData or equivalent).
  • Clear all cache data related to BONELAB.
  • Restart Thunderstore and rebuild your modlist manually to ensure no outdated references are causing issues.

7. Reinstall Thunderstore and Mods

If all else fails, a complete reset may be necessary:

  1. Uninstall Thunderstore Mod Manager completely from your system.
  2. Manually delete any remaining Thunderstore-related folders from AppData or Game directory.
  3. Reinstall Thunderstore and re-add mods one-by-one, carefully monitoring each addition to detect the return of the error.

Preventing the CP2ILL Error in the Future

Once you have BONELAB running again without this error, take preventative measures to keep your system stable:

  • Enable auto-backups in Thunderstore so you can revert to working profiles easily.
  • Check for mod updates weekly — some authors remove or update dependencies.
  • Read mod pages carefully before download — particularly the required dependencies list.
  • Stick to one profile for active use unless you’re an advanced user managing separate builds.

Frequently Asked Questions (FAQ)

What exactly is CP2ILL in BONELAB?
CP2ILL appears to be a dependency or internal component used by another mod. It is not a visible standalone mod in most Thunderstore setups.
Is CP2ILL a virus or malware?
No, it is not. It’s a legitimate, albeit obscure, mod component that BONELAB is trying to load. The loading failure is due to mod configuration or version issues, not malware concerns.
Should I reinstall BONELAB if I get this error?
Not immediately. Try the step-by-step solutions first. Reinstalling the game is more of a last resort and usually unnecessary if the problem is mod-related.
Can I fix this by switching mod managers?
Possibly, but not recommended. Thunderstore is the most actively supported for BONELAB. You may want to try alternative profiles or clear caches first before switching over to something like R2Modman or manual configurations.
How do I report a broken mod on Thunderstore?
Go to the specific mod’s page on Thunderstore.io, scroll to the comments or GitHub link, and submit an issue or feedback to the author.

Dealing with mod errors like “Failed to Load CP2ILL” in BONELAB can be frustrating, but with the right troubleshooting steps, it’s more than fixable. Stay updated, keep profiles clean, and don’t be afraid to ask the modding community for help when things don’t go as planned.