Thunderstore is a popular mod manager and delivery platform for games like Valheim, Risk of Rain 2, and others. However, users occasionally encounter frustrating issues when trying to manage or install mods. One commonly reported problem is the “Error Checking Existence” message, which halts smooth mod deployment and can lead to confusion. Understanding what causes this issue and how to solve it can significantly improve your modding experience.
TL;DR
If you’re encountering the “Error Checking Existence” in Thunderstore, it’s usually due to missing files, incorrect installation paths, or network/server instability. To fix it, verify your installation, clear mod manager caches, and ensure you have the correct permissions. Also make sure Thunderstore’s backend is not experiencing outages. This guide walks you through detailed steps to resolve the issue efficiently and prevent it from happening again.
What Is the “Error Checking Existence” Problem?
When using a Thunderstore mod manager such as r2modman or Thunderstore Mod Manager, this error typically pops up when the application tries to verify if certain mod files or paths already exist before proceeding with installation or updates. The error message might appear vague, but it refers to the application’s inability to locate or assess the expected location or item—be it a directory, file, or network resource.
Common Symptoms:
- Installation of new mods fails with a red warning message.
- Existing mod profiles cannot load correctly.
- Syncing or updating mods hangs indefinitely or crashes the manager.
Potential Causes of the Error
There are several reasons why this error might occur:
- Corrupted installation paths – The game or mod manager may not be pointing to the correct folder.
- File permission issues – Your operating system may be blocking certain reads and writes.
- Interrupted downloads – Partial or failed downloads confuse the file checker logic.
- Server-side problems – Thunderstore servers could be undergoing maintenance or suffering outages.
- Conflict between mods – Two mods trying to alter the same assets might confuse the existence-check process.
Step-by-step Guide to Fix the Error
Step 1: Verify Your Game Installation Path
One of the most common causes of the “Error Checking Existence” message is that the mod manager is pointed at the wrong game directory. To ensure you’re not experiencing this issue:
- Open your Thunderstore Mod Manager or r2modman.
- Go to Settings > Locations.
- Make sure the game path points precisely to the root directory of your installed game—not a subfolder, not Steam’s general directory.
- If necessary, click Change and manually browse to the correct folder.
This step alone resolves a large number of error messages related to file and path mismatch.
Step 2: Clear Local Cache and Temporary Files
Corrupted or outdated cache files can mislead the mod manager when checking for file paths. Here’s how to clear your local cache:
- Exit the Thunderstore mod manager completely.
- Navigate to the following directory depending on your OS:
- For Windows:
C:\Users\[YourName]\AppData\Roaming\Thunderstore Mod Manager - For Linux:
~/.config/Thunderstore Mod Manager/ - Locate and delete the Cache and Temp folders.
- Restart your mod manager and try again.
Note: Clearing cache won’t delete your mods but could delay the first load while settings are re-cached.
Step 3: Check for Mod Conflicts
If you have recently installed multiple mods or updated existing ones, there’s a chance they might be incompatible or redundantly altering the same files.
To troubleshoot:
- Launch the mod manager.
- Disable all mods.
- Enable one mod at a time and launch the game to see if the error appears.
- Continue methodically until the conflicting mod is identified.
Once identified, consider checking the mod’s documentation or Thunderstore page to see if other users have reported similar incompatibilities.
Step 4: Run As Administrator
File permission errors are surprisingly common, especially if your system uses certain antivirus or UAC (User Account Control) settings. Running your mod manager as administrator can bypass many of these issues:
- Right-click the mod manager shortcut.
- Select Run as Administrator.
- Try replicating the error condition.
If this resolves the issue, consider setting the application to always run as administrator by going to Properties > Compatibility and checking the box labeled “Run this program as administrator.”
Step 5: Confirm Thunderstore Server Status
Although rare, issues can arise from the Thunderstore platform itself. Mod checking or download-related actions could fail if the servers are temporarily down.
To verify:
- Visit Thunderstore Status Page to check for any ongoing outages.
- Join Thunderstore’s official Discord or forums to see if other users have reported similar issues.
Step 6: Reinstall the Mod Manager
If all else fails, uninstalling and reinstalling your mod manager could fix corrupted core files or misconfigured settings causing the check-existence error.
- Backup any important mod profiles or configuration files.
- Uninstall the mod manager via Control Panel or application manager.
- Download the latest version from the official site.
- Reinstall and restore saved profiles if available.
Preventing the Error in the Future
Here are some best practices to avoid running into the “Error Checking Existence” problem again:
- Keep your mod manager updated – Always use the latest version to ensure compatibility.
- Avoid mod redundancy – Double-check mods that affect similar assets or functions before installing several at once.
- Maintain a clean install – Avoid altering game files manually outside of the mod manager whenever possible.
- Use trusted mods – Stick to popular or community-verified mods to minimize issues caused by poor development practices.
Conclusion
The “Error Checking Existence” message in Thunderstore can be a significant hurdle if you’re eager to enhance your gameplay experience with mods. But with a methodical approach—verifying your paths, clearing outdated cache, checking for mod conflicts, and ensuring proper permissions—you can resolve this issue and return to enjoying your game.
If the error persists even after trying all the recommended steps, it may be best to consult the mod manager’s GitHub issues section or engage with the Thunderstore support community. Many users have experienced and solved similar issues, and tapping into those insights can save time and frustration.
Stay patient, stay updated, and mod responsibly.