OpenClaw is an open-source AI agent tool designed to configure and manage AI agents. In real-world use, users often encounter startup failures or proxy connection errors. This article breaks down the most common error codes and their root causes, providing validated fix steps to help you restore OpenClaw to normal operation quickly.
Startup Failure: Configuration File Errors & Missing Dependencies
When OpenClaw shows "config.json parse error" or "missing required field" during startup, it usually means the configuration file has formatting issues or lacks key parameters. Check that your config.json includes required fields like api_key, model_endpoint, and proxy_mode, and use a JSON validator to confirm there are no extra commas or mismatched quotes. If you see a "dependency not found" error, it means the required Python packages are not installed—simply run pip install -r requirements.txt to resolve it.
Some users on Windows systems may also encounter a "permission denied" error. This happens because OpenClaw needs permission to read system proxy settings. Run your terminal as an administrator, or check whether your antivirus software is blocking port listening permissions.
Abnormal Proxy Connections: Port Conflicts & Proxy Nesting
When OpenClaw reports "port already in use," it means the default port (e.g., 8080) is taken by another program. Use lsof -i :8080 (Linux/macOS) or netstat -ano | findstr 8080 (Windows) to find and terminate the occupying process, or switch to a different port by adding --port 8081 to your startup command. If you see a "connection refused" error, verify that the target AI service address and port are correctly entered, and check whether your local firewall is allowing the connection.
For users who route traffic through a system-level proxy, OpenClaw may struggle to properly separate internal and external network traffic. It is recommended to set proxy_mode to exclusive or direct in config.json to avoid proxy nesting.