Claude Error Troubleshooting: Common Error Codes and Solutions

Encountering error codes or functional issues while using Claude is common. This article summarizes the most frequent types of errors and their solutions, helping you quickly resume your conversation.

Login & Account Errors

Seeing “Invalid credentials” or “Account locked” usually means you’ve entered the wrong password multiple times or logged in from a different location, triggering security controls. Try resetting your password and waiting 15 minutes before retrying. If your account is locked, use the unlock link sent to your linked email, or contact official support.

Additionally, if you use third-party login (e.g., Google, Apple), an expired authorization can also cause login failure. Make sure you’re already logged into the corresponding platform account in your browser.

API Request Errors

When calling the Claude API, “401 Unauthorized” or “429 Too Many Requests” are the most common errors. The former indicates an invalid or expired API key—check your key for accuracy and regenerate if needed. The latter means your request frequency exceeds the free tier limit. Reduce the request interval or upgrade to a Pro plan for higher quotas.

If you encounter “500 Internal Server Error,” it’s typically a temporary server issue. Wait a few minutes and retry. We recommend implementing an automatic retry mechanism (e.g., exponential backoff) in your code to minimize manual intervention.

Conversation & Response Issues

If a conversation suddenly stops or you see “Content filtered,” the input has triggered security review. Check for sensitive words, excessive special characters, or content exceeding the context length. Simplify your input and resend.

If responses are extremely slow or incomplete, network fluctuations may be the cause. Try switching networks (e.g., from mobile 4G to Wi-Fi), or clear your browser cache and cookies. Heavy users can also disable browser extensions (e.g., ad blockers) before retrying.

Payment & Subscription Errors

Paying users may see “Payment declined” or “Subscription not active.” Check your card balance, expiration date, and billing address to ensure it matches the card’s registered address. If using a virtual card, confirm that the card type is supported by Claude.

If your subscription status is abnormal, first log out and log back in, then go to the “Billing” page to verify your plan. If the issue persists, contact support with your transaction ID; it’s usually resolved within 1–2 business days.