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Claude Code Troubleshooting Guide

Complete troubleshooting guide for Claude Code installation, configuration, and usage issues. Get step-by-step solutions for common problems and error messages.

Installation Issues​

Node.js Version Problems​

Problem: Claude Code installation fails with Node.js version errors Solution:

  1. Check your Node.js version: node --version
  2. Claude Code requires Node.js 18.0 or higher
  3. Update Node.js from nodejs.org
  4. Restart your terminal after installation
  5. Retry Claude Code installation

Permission Errors During Installation​

Problem: "Permission denied" or "EACCES" errors during npm install Solution:

For macOS/Linux:

# Fix npm permissions
sudo chown -R $(whoami) ~/.npm
# Or install with sudo (not recommended)
sudo npm install -g @anthropic-ai/claude-code

For Windows:

# Run Command Prompt as Administrator
npm install -g @anthropic-ai/claude-code

Installation Hangs or Times Out​

Problem: Installation process freezes or network timeouts Solution:

  1. Check internet connection
  2. Try with different npm registry:
npm install -g @anthropic-ai/claude-code --registry https://registry.npmjs.org/
  1. Clear npm cache: npm cache clean --force
  2. Restart and retry installation

Authentication and Configuration Issues​

API Key Problems​

Problem: "Invalid API key" or authentication failures Solution:

  1. Verify API key at console.anthropic.com
  2. Reconfigure Claude Code: claude config
  3. Check environment variables:
echo $ANTHROPIC_API_KEY
  1. Ensure no extra spaces or characters in API key

Subscription Authentication Issues​

Problem: Can't authenticate with Claude Max/Pro subscription Solution:

  1. Ensure you're logged into the correct Claude account
  2. Clear browser cookies and retry authentication
  3. Use incognito/private browsing mode
  4. Contact Anthropic support if subscription isn't recognized

Configuration File Problems​

Problem: Claude Code ignores configuration settings Solution:

  1. Check configuration file location: ~/.claude.json
  2. Verify JSON syntax is valid
  3. Reset configuration: claude config --reset
  4. Manually edit ~/.claude.json if needed

Connection and Network Issues​

Claude Code Not Responding​

Problem: Claude Code starts but doesn't respond to commands Solution:

  1. Restart Claude Code - Exit and restart the application
  2. Check internet connection - Test with other websites
  3. Verify API status - Check status.anthropic.com
  4. Clear session - Use /clear command to start fresh
  5. Update Claude Code - Run npm update -g @anthropic-ai/claude-code

503 Service Unavailable Errors​

Problem: Getting "503 no healthy upstream" errors Solution:

  • Wait 2-5 minutes - These are temporary server issues
  • Check service status - Visit status.anthropic.com
  • Don't reinstall - This won't fix server-side problems
  • Try again later - Server issues usually resolve quickly

Internal Server Errors​

Problem: "Internal server error" messages Solution:

  • Wait 1-3 minutes - Backend processing issues resolve automatically
  • Don't change configuration - This is a server-side problem
  • Check community reports - Visit r/ClaudeAI for widespread issues
  • Avoid reinstalling - Won't help with server problems

Performance Issues​

Slow Response Times​

Problem: Claude Code responses are very slow Solution:

  1. Switch models - Try Claude 4 Sonnet for better speed
  2. Reduce context - Use /compact to summarize conversation
  3. Smaller files - Break large files into smaller components
  4. Native platform - Use Linux/macOS instead of WSL when possible
  5. Adequate RAM - Ensure 16GB+ RAM for optimal performance

High Memory Usage​

Problem: Claude Code consuming too much system memory Solution:

  1. Restart Claude Code regularly for long sessions
  2. Use /clear to reset conversation history
  3. Close other applications to free up RAM
  4. Monitor usage with system activity monitor
  5. Consider upgrading RAM if consistently hitting limits

Context Window Issues​

Problem: "Context window full" or memory limit errors Solution:

  1. Use /compact with specific instructions:
/compact keep only the main function names and error messages
  1. Start fresh with /clear command
  2. Smaller chunks - Work on one feature at a time
  3. Sub-agents - Use Task tool for parallel processing
  4. File organization - Use many small files instead of large ones

Platform-Specific Issues​

Windows WSL Problems​

Problem: Claude Code performance issues on Windows WSL Solution:

  1. Update WSL2: wsl --update
  2. Optimize WSL memory - Configure .wslconfig:
[wsl2]
memory=8GB
processors=4
  1. Use Windows Terminal for better performance
  2. Store files in Linux filesystem (/home/ not /mnt/c/)
  3. Consider native Linux for best performance

VS Code Integration Issues​

Problem: Claude Code VS Code extension not working Solution:

  1. Install extension from VS Code Marketplace
  2. Restart VS Code completely after installation
  3. Check WSL connection - Ensure VS Code connects to WSL
  4. Use /ide command from external terminal to connect
  5. Verify file paths - Ensure working in correct directory

File and Project Issues​

Permission Denied on File Operations​

Problem: Can't read/write files in project directory Solution:

  1. Check file permissions: ls -la
  2. Fix ownership: sudo chown -R $(whoami) .
  3. Verify directory access - Ensure Claude Code can access project folder
  4. Use --add-dir flag for multiple directories
  5. Configure allowed tools in ~/.claude.json

Large File Handling Problems​

Problem: Claude Code struggles with large files Solution:

  1. Split large files into smaller, logical components
  2. Use specific ranges when reading large files
  3. Exclude build artifacts - Don't process generated files
  4. Focus requests - Ask about specific functions, not entire files
  5. Create summaries of large codebases in CLAUDE.md

Model and Feature Issues​

Model Switching Problems​

Problem: Can't switch between Claude models Solution:

  1. Use correct syntax: claude --model claude-sonnet-4-20250514
  2. Check subscription - Ensure access to requested model
  3. Restart session after model change
  4. Verify model names - Use exact model identifiers
  5. Update Claude Code - Newer versions support more models

Sub-agent Issues​

Problem: Sub-agents not working or hanging Solution:

  1. Check internet connection - Sub-agents need network access
  2. Simplify tasks - Break complex requests into smaller parts
  3. Monitor progress - Look for flashing bubbles in UI
  4. Manual tasks - Do critical work in main thread
  5. Restart if stuck - Exit and restart Claude Code

Advanced Troubleshooting​

Complete Reset Procedure​

If all else fails, try a complete reset:

  1. Uninstall Claude Code:
npm uninstall -g @anthropic-ai/claude-code
  1. Remove configuration:
rm ~/.claude.json
rm -rf ~/.claude/
  1. Clear npm cache:
npm cache clean --force
  1. Reinstall fresh:
npm install -g @anthropic-ai/claude-code
claude config

Log Collection for Support​

To get help from support, collect these details:

  1. Claude Code version: claude --version
  2. Node.js version: node --version
  3. Operating system: uname -a (Linux/Mac) or ver (Windows)
  4. Error messages - Copy exact error text
  5. Configuration - Share ~/.claude.json (remove API keys)

Getting Additional Help​

Community Resources​

Official Support​

Prevention Tips​

  • Keep updated - Regularly update Claude Code and Node.js
  • Monitor status - Check service status before major sessions
  • Backup configuration - Save working ~/.claude.json files
  • Test changes - Verify configuration changes in small projects first
  • Regular restarts - Restart Claude Code periodically in long sessions

This troubleshooting guide covers the most common Claude Code issues. For additional help, check the FAQ or visit the community resources.

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