Troubleshooting#

This guide helps resolve common issues when using Cheolsu Proxy.

🚫 Proxy Won't Start#

Port Already in Use#

Symptoms: "Port is already in use" error message

Solution:

1. Try changing to a different port number (e.g., 8080, 9000)
2. Change port in Settings → Proxy Port
3. Restart proxy

Firewall Blocking#

Symptoms: Proxy starts but connections fail

Solution:

1. Windows: Allow Cheolsu Proxy in Windows Defender Firewall
2. macOS: Allow in System Preferences → Security & Privacy → Firewall
3. Also allow in antivirus software settings

Administrator Privileges Required#

Symptoms: "Insufficient privileges" error

Solution:

1. Right-click Cheolsu Proxy
2. Select "Run as administrator"
3. Or log in with administrator account

🌐 Can't Access Websites#

Check Browser Proxy Settings#

Symptoms: Cannot access any websites

Solution:

1. Verify browser proxy settings are correct
2. HTTP Proxy: 127.0.0.1:8100 (or your configured port)
3. HTTPS Proxy: 127.0.0.1:8100 (or your configured port)

Check Internet Connection#

Symptoms: Works without proxy but fails with proxy

Solution:

1. Check internet connection status
2. Verify DNS settings (recommend 8.8.8.8, 1.1.1.1)
3. Temporarily stop proxy and test direct connection

Specific Sites Only#

Symptoms: Some sites work, others don't

Solution:

1. Check if the site blocks proxies
2. Check domain filtering in proxy settings
3. Test with different browser

🔒 HTTPS Site Issues#

Certificate Warnings#

Symptoms: "Your connection is not secure" warning

Solution:

1. Verify certificate is properly installed
2. Click "Regenerate Certificate" in Settings → Certificates
3. Restart browser

Certificate Installation Failed#

Symptoms: Certificate install button doesn't work

Solution:

1. Run Cheolsu Proxy with administrator privileges
2. Temporarily disable antivirus software
3. Use manual installation method (see Certificate Management Guide)

Warnings Only in Some Browsers#

Symptoms: Works in Chrome but shows warnings in Firefox

Solution:

1. Check certificate store for each browser
2. Firefox: Settings → Privacy & Security → Certificates
3. Chrome: Settings → Advanced → System → Manage certificates

📱 Mobile Connection Issues#

Mobile Can't Connect to Proxy#

Symptoms: Mobile device can't connect after proxy setup

Solution:

1. Ensure PC and mobile are on same Wi-Fi
2. Verify PC's IP address is correct
3. Allow mobile IP in PC's firewall

Mobile Certificate Installation Issues#

Symptoms: Can't access HTTPS sites on mobile

Solution:

1. Transfer certificate file to mobile
2. Install certificate on mobile
3. Enable certificate trust settings

⚡ Performance Issues#

Slow Connection#

Symptoms: Websites load very slowly

Solution:

1. Set log level to "Simple"
2. Remove unnecessary domain filtering
3. Restart proxy

High Memory Usage#

Symptoms: Cheolsu Proxy uses too much memory

Solution:

1. Clean up log files
2. Limit concurrent connections
3. Restart program

🔧 Settings Issues#

Settings Not Saved#

Symptoms: Settings reset after restart

Solution:

1. Run Cheolsu Proxy with administrator privileges
2. Check settings file permissions
3. Check if antivirus is blocking settings files

Auto Start Not Working#

Symptoms: Cheolsu Proxy doesn't auto-start with computer

Solution:

1. Check "Auto-start on system boot" in Settings → General
2. Windows: Check Task Scheduler
3. macOS: Check Login Items

📊 Log Issues#

No Logs Displayed#

Symptoms: Nothing shows in Logs tab

Solution:

1. Set log level to "Detailed"
2. Restart proxy
3. Access websites to generate logs

Log Files Too Large#

Symptoms: Log files become very large

Solution:

1. Set log level to "Simple"
2. Enable log file auto-rotation
3. Regularly delete log files

🆘 Advanced Troubleshooting#

Network Diagnostics#

# Test proxy connection
curl -x http://127.0.0.1:8100 http://httpbin.org/ip

# Check port usage (Windows)
netstat -an | findstr :8100

# Check port usage (macOS)
lsof -i :8100

Log File Locations#

• Windows: %APPDATA%\CheolsuProxy\logs\
• macOS: ~/Library/Logs/CheolsuProxy/

Settings File Locations#

• Windows: %APPDATA%\CheolsuProxy\config\
• macOS: ~/Library/Application Support/CheolsuProxy/config/

📞 Additional Help#

If Problem Persists#

1. Search for similar issues in GitHub Issues
2. When creating new issue, include:
   • Operating system and version
   • Cheolsu Proxy version
   • Error message screenshots
   • Steps to reproduce problem

Useful Links#

• GitHub Issues

Now you can use Cheolsu Proxy freely! If problems persist, feel free to ask for help anytime.