Troubleshooting Launch Response Error Codes

This guide helps you to quickly diagnose and resolve response errors in Contentstack Launch, whether they originate from the CDN edge layer or your backend serverless functions (the origin). For each issue, we provide the specific error message, a detailed explanation of its cause, and steps to resolve the issue.

A CDN edge error occurs when the request reaches the CDN layer, but the Launch Edge Function fails to execute correctly. This error returns a 500 response.

Cause:
The Edge Function encountered an unhandled exception or returned an invalid or malformed response.

Resolution:

• Check the Launch Server Logs associated with the Edge Function’s execution to identify what caused the failure.
• Review the Edge Function’s logic to ensure there are no unhandled exceptions.
• Ensure the function always returns a valid, properly structured response.

Origin errors occur when a request reaches your backend serverless functions, but an issue prevents them from processing the request or returning a valid response.

Error:
Internal Server Error CF001: The server failed to start. Check the Launch Server logs for details.

Launch attempted to start your project’s server, but the process failed to initialize. This error returns a 500 response.

Cause:
An incorrect server command, missing or invalid build output, an unexpected error that prevents the server from starting, or an application crash caused by running out of memory.

Resolution:

• Check the Launch Server Logs or your configured Log Targets.
• Verify that the server command is correct and can start successfully in your local environment.
• Fix configuration or build issues and redeploy the project.

Error:
Internal Server Error CF002: A general internal error occurred. Try again, or contact Contentstack Support if the issue persists.

This error occurs when the Launch infrastructure encounters an unexpected issue while processing the request. It returns a 500 response.

Cause:
An unexpected issue within the Launch platform prevented the request from completing successfully.

Resolution:

• Retry the request after a short period.
• If the issue persists, contact Contentstack Support and include relevant logs or request details for further investigation.

Error:
Bad Gateway CF003: The total size of the response headers exceeded the limit. Check and reduce their size.

Your server-side application returned response headers whose combined size was greater than the allowed limit. This error returns a 502 response.

Cause:

• Large cookies.
• Too many Set-Cookie headers.
• Oversized custom headers (tokens, metadata, etc.).

Resolution:

• Reduce the overall size of your response headers.
• Minimize or remove large cookies.
• Review and optimize custom headers to ensure they remain within supported limits.

Error:
Internal Server Error CF004: No valid response from the server. Check the Launch Server Logs and try again.

This error occurs when the origin function executes but does not return a valid HTTP response. It returns a 500 response.

Cause:

• Failure to fetch data from external sources.
• Runtime errors that prevented the response from being generated.

Resolution:

• Review the Launch Server Logs or your configured Log Targets to identify the failure.
• Ensure the application always returns a valid HTTP response, including status code, headers, and body.
• Fix the underlying issue and redeploy the project.