Claude Error Code Troubleshooting: Fix Login Timeout & API Rate Limit Issues

1. Login & Account Errors

The most common login errors when using Claude are "Invalid credentials" and "Account locked." If you keep entering the correct password but can't log in, first check whether your network is stable, then confirm your account hasn't been temporarily locked due to too many failed attempts. Claude freezes login access for 15 minutes after 5 consecutive incorrect password entries—just wait and try again. If you see "Email not verified," open your registration email and click the verification link; some email providers may mistakenly send it to spam.

Another frequent issue is the "Session expired" pop-up appearing during regular use. This happens because your token has expired after a long idle period. Simply refresh the page or log out and log back in to restore access. Enabling your browser's password manager can help avoid manual input errors.

2. Message Send & Response Errors

If you send a query and Claude either doesn't reply or shows a "Request failed" error, start by checking the API status page. If the service is running normally, the problem is likely an unstable connection between your local network and Claude's servers. Switching network nodes or using a VPN/accelerator usually resolves this. When you see "Context length exceeded," your current conversation history is too long and the context window is full. Delete some older messages or start a new conversation to continue.

Some users also encounter "Model not available" errors. This means the model version you requested (e.g., Claude 3.5 Sonnet) is temporarily overloaded or undergoing maintenance. Switch to another available model (such as Claude 3 Haiku) and you can keep using the service normally. Switch back once the original model is restored.

3. API Call & Rate Limit Issues

Developers using the Claude API often see the "rate_limit_exceeded" error, meaning your request frequency has exceeded the per-minute or per-hour quota. The solution is to reduce your request rate or implement exponential backoff retry logic in your code. If you receive "invalid_api_key," double-check that the API key is copied completely with no extra spaces, and confirm the key hasn't expired—free keys are typically valid for 30 days.

Another tricky error is "billing_limit_reached," indicating your API consumption has exceeded the budget limit you set. Log in to the Claude console to adjust your budget or top up your account to remove the restriction. It's recommended to set a conservative budget alert value before going live to avoid unexpected downtime.

4. Other Common Errors & General Troubleshooting

Occasionally you might encounter "500 Internal Server Error" or "503 Service Unavailable." These are temporary server-side faults that usually resolve on their own within a few minutes. Check the official Claude status page (status.anthropic.com) to see if the issue is global or isolated. A "400 Bad Request" error typically indicates a malformed request parameter—carefully compare your JSON structure against the API documentation. Finally, if none of these solutions work, try clearing your browser cache, switching devices, or contacting Claude support. Providing a screenshot of the error can significantly speed up the resolution process.