Menu
  Log out
 

Core Keeper Server Troubleshooting Guide - Core Keeper Wiki

Core Keeper Guide • Updated Jan 9, 2026

Core Keeper Server Troubleshooting Guide

Comprehensive guide to diagnosing and fixing common Core Keeper dedicated server issues. From connection problems to performance bottlenecks, save corruption, mod conflicts, and world generation errors, this guide provides step-by-step solutions for server administrators.

Quick Tip: Most Core Keeper server issues can be resolved by checking port forwarding, verifying server configuration files, ensuring all players have the same game version, and managing world save compatibility.

Common Connection Issues

1. "Failed to Connect" or "Connection Timed Out" Error

Symptoms:

  • Players cannot connect to server
  • "Failed to connect" or "Connection timed out" message appears
  • Server shows in browser but connection fails
  • Players can connect locally but not remotely

Solutions:

  1. Check Port Forwarding: Ensure port 27015 (default UDP) is properly forwarded on your router.
  2. Verify Firewall Settings: Add exceptions for Core Keeper server executable in Windows Firewall or configure iptables on Linux.
  3. Test Local Connection: Try connecting from a device on the same network to rule out internet issues.
  4. Check Server Status: Verify the server process is running with netstat -tulpn | grep 27015 (Linux) or Resource Monitor (Windows).
  5. Update Server Files: Ensure server is updated to latest stable version using SteamCMD (App ID: 1963720).

2. Server Not Showing in Server Browser

Symptoms:

  • Server doesn't appear in Core Keeper server browser
  • Direct IP connection works but browser doesn't show server
  • Server visibility set to "Public" but not listed
  • Intermittent visibility in browser

Solutions:

  1. Enable Steam Query: Ensure server is launched with proper Steam networking flags.
  2. Check Query Port: Verify port 27016 (if used for queries) is open and accessible.
  3. Wait for Registration: Steam server browser can take 5-15 minutes to register new servers.
  4. Server Name Format: Avoid special characters in server name that might break browser listing.
  5. Use Server Browser Commands: Try refreshing browser or restarting game client.

Performance Problems

3. Server Lag and High Ping

Symptoms:

  • Delayed player actions and enemy movements
  • High ping for all connected players
  • World saving causes temporary freezes
  • Chunk loading lag during exploration

Solutions:

  1. Optimize Server Settings: Reduce MaxPlayers or adjust performance settings in server.cfg.
  2. Increase Memory Allocation: Ensure server has adequate RAM (minimum 4GB for 10 players).
  3. Reduce View Distance: Lower ViewDistance in server settings to reduce chunk loading.
  4. Schedule Regular Restarts: Daily server restarts clear memory leaks and improve performance.
  5. Use Performance Optimizations: Consider dedicated hosting with SSD storage for faster world saves.

4. High CPU/Memory Usage

Symptoms:

  • Server process using excessive CPU (90%+)
  • Memory usage constantly increasing over time
  • Server becomes unresponsive after extended uptime
  • Performance degradation with many active chunks

Solutions:

  1. Limit Player Count: Reduce MaxPlayers setting to match server capabilities.
  2. Optimize World Size: Consider using smaller world sizes if experiencing performance issues.
  3. Regular Restarts: Schedule daily server restarts to clear memory leaks.
  4. Monitor with Tools: Use htop (Linux) or Process Explorer (Windows) to identify resource hogs.
  5. Upgrade Hardware: Consider moving to dedicated hosting with better CPU/RAM resources.

Save and World Issues

5. World Corruption or Save Data Loss

Symptoms:

  • World fails to load on server startup
  • Characters or structures missing after server restart
  • "Failed to load world" error message
  • Map chunks not loading or appearing corrupted

Solutions:

  1. Restore from Backup: Use Supercraft's automated backups or manual backup files in saves/ directory.
  2. Verify File Permissions: Ensure server has write access to save directory.
  3. Check Disk Space: Ensure adequate free space for world saves (minimum 2GB).
  4. Use Save Repair Tools: Consider using community tools for Core Keeper save file repair.
  5. Prevent Corruption: Always use proper shutdown procedure rather than killing process.

6. Character and Inventory Data Issues

Symptoms:

  • Character items or progression missing after server transfer
  • Inventory reset or items disappearing
  • Skill levels reset or decreased
  • Duplicate characters appearing

Solutions:

  1. Backup Save Files: Regularly backup entire saves/ directory including player data.
  2. Check Save Compatibility: Ensure save files match server version (major updates may break saves).
  3. Avoid Cross-Server Transfers: Character data may not be compatible between different server configurations.
  4. Manual Restoration: Replace corrupted player data with backups from known good state.
  5. Preventive Measures: Enable automatic backups and test restore procedures regularly.

Mod-Related Problems

7. Mod Compatibility Issues

Symptoms:

  • Server crashes on startup with mods enabled
  • Players cannot connect due to mod mismatch
  • Game features broken after mod installation
  • Inconsistent behavior between server and clients

Solutions:

  1. Verify Mod Versions: Ensure all mods are updated to latest versions compatible with Core Keeper version.
  2. Check Load Order: Some mods require specific load order in server configuration.
  3. Test Mods Individually: Disable all mods, then enable one at a time to identify conflicts.
  4. Check Workshop IDs: Ensure server and clients subscribe to same Workshop IDs (not local mod files).
  5. Use Mod Manager: Consider using mod managers for consistent deployment across server and clients.

8. Steam Workshop Mod Problems

Symptoms:

  • Workshop mods not downloading to server
  • Mod updates not applying automatically
  • Clients missing required mods
  • Mod version mismatches between server and clients

Solutions:

  1. Verify SteamCMD Setup: Ensure SteamCMD is properly configured with login credentials for Workshop downloads.
  2. Check Workshop IDs: Verify correct Workshop IDs are specified in server configuration.
  3. Manual Mod Installation: Consider manually installing mods to server directory for better control.
  4. Update Schedule: Schedule regular server restarts to check for mod updates.
  5. Client Communication: Inform players of mod changes and required updates.

Configuration and Settings Issues

9. Server Settings Not Applying

Symptoms:

  • Changes to server.cfg not taking effect
  • Server reverting to default settings after restart
  • Configuration file being overwritten
  • Settings inconsistent between server and clients

Solutions:

  1. Verify File Location: Ensure editing correct server.cfg in server root directory.
  2. Check Configuration Syntax: Ensure no syntax errors in configuration file.
  3. File Permissions: Server needs write access to configuration files.
  4. Restart Server: Most settings require server restart to take effect.
  5. Backup Original: Always backup configuration before making changes.

10. World Generation Problems

Symptoms:

  • World not generating properly
  • Missing biomes or resources
  • World seed not producing expected results
  • Generation errors or crashes

Solutions:

  1. Check World Seed: Some seeds may produce problematic worlds; try different seeds.
  2. Verify Game Version: Ensure server matches client version for world generation algorithms.
  3. Allocate More Memory: World generation may require additional RAM for large worlds.
  4. Test Generation Locally: Generate world in single-player first to verify seed works.
  5. Community Resources: Check Core Keeper community for known good seeds and generation tips.

Network and Firewall Configuration

# Required Ports for Core Keeper Server Port 27015 (UDP) - Game traffic (default, configurable) Port 27016 (UDP) - Optional query/RCON port # Linux iptables rules sudo iptables -A INPUT -p udp --dport 27015 -j ACCEPT sudo iptables -A INPUT -p udp --dport 27016 -j ACCEPT # Windows Firewall PowerShell New-NetFirewallRule -DisplayName "Core Keeper 27015-27016" -Direction Inbound -Protocol UDP -LocalPort 27015-27016 -Action Allow # Common server.cfg settings MaxPlayers = 10 Port = 27015 ServerName = "My Core Keeper Server" WorldSize = Medium

Diagnostic Commands and Tools

Server Console Commands

# Check server status netstat -tulpn | grep 27015 # Monitor server process (Linux) top -p $(pgrep CoreKeeper) # View server logs (typical locations) tail -f ~/.config/unity3d/Pugstorm/CoreKeeperServer/Logs/*.log tail -f "C:\Users\[User]\AppData\LocalLow\Pugstorm\CoreKeeperServer\Logs\*.log" # Test network connectivity nc -zvu your_server_ip 27015 # Check disk space df -h /path/to/server

Client-Side Diagnostics

  • Steam Network Diagnostics: Steam → Settings → Downloads → Clear Download Cache
  • Verify Game Files: Steam Library → Core Keeper → Properties → Local Files → Verify Integrity
  • Check Firewall: Ensure Core Keeper client is allowed through Windows Defender Firewall
  • Update Network Drivers: Ensure network adapter drivers are up to date
  • Client Logs: Check %UserProfile%\AppData\LocalLow\Pugstorm\CoreKeeper\Logs\ for connection errors

Preventative Measures

Best Practices to Avoid Issues:

  1. Regular Backups: Schedule automated daily backups of world saves, configuration files, and player data.
  2. Update Management: Test game updates on a staging server before deploying to production.
  3. Monitor Resources: Use monitoring tools to track CPU, memory, and disk usage trends.
  4. Document Configuration: Keep records of server settings, mod lists, and custom changes.
  5. Community Communication: Inform players of scheduled maintenance, updates, and expected downtime.
  6. Moderation Team: Establish clear rules and admin procedures for server management.

When to Seek Help

If you've tried all troubleshooting steps and still experience issues:

  • Check Official Channels: Core Keeper Discord server, Pugstorm support, official forums
  • Community Resources: Reddit r/CoreKeeper, Core Keeper community wiki, Steam community guides
  • Hosting Provider: Contact Supercraft support for dedicated server assistance and diagnostics
  • Log Collection: Gather server logs, client logs, console outputs, and error messages before seeking help
  • Bug Reporting: Report persistent bugs to Pugstorm with detailed reproduction steps

Final Tip: Core Keeper servers are relatively stable but can experience issues with mods, world generation, and network configuration. Most problems are solvable with systematic troubleshooting: start with basic connectivity, then configuration, then mods, then hardware/resources.

Need professional Core Keeper server hosting with automated troubleshooting? Launch your Core Keeper server with Supercraft for optimized performance and 24/7 support.

← Back to Core Keeper Guides
Top