Self-signed SSL certificate troubleshooting

Troubleshooting Self-signed SSL Certificate Issues and More in Postman

Looking for help with the error, “self-signed SSL certificates are being blocked,” or a related error? Well, you’ve come to the right place.

Perhaps you’re using Postman and encountered the “Could not get any response” error pictured below:  

Let’s get you back on track with a few ways that you can troubleshoot this unexpected behavior in Postman.

Postman Console

The Postman Console works the same way as a web browser’s developer console and is a great place to go to get more detailed information about what’s going on under the hood. It should be your first step in identifying the issue you’re seeing while you’re trying to debug. 

Here’s all of the information that the Postman Console logs:

  • The actual request that was sent, including all underlying request headers and variable values, etc.
  • The exact response sent by the server before it is processed by Postman 
  • The proxy configuration and certificates used for the request
  • Error logs from tests or pre-request scripts
  • The console.log() from inside scripts

Connectivity issues

You may see the “Could not get any response” message if Postman is unable to connect to your server. To check if you’re having connectivity issues, try opening your server address in a web browser. If you’re able to open it in your browser then potential issues could include:

Firewall issues: Some firewalls are configured to block non-browser connections – check with your network admins.

Proxy configuration: If you’re using a proxy server to make requests, ensure that it’s configured correctly. Postman will use the system proxy by default – custom proxy info can also be added if it’s needed for specific requests or domains. You can see more information about the proxy server using the Postman console.

SSL certificate issues: If you’re using HTTPS connections, you can turn off SSL verification under Postman settings. If that doesn’t resolve the issue, your server may be using a client-side SSL connection which you can configure under Postman Settings. Check the Postman Console to ensure that the correct SSL certificate is being sent to the server. 

Client certificate issues: The server might require client certificates. You can resolve this by adding a client certificate under Postman Settings.

Incorrect request URLs: If your request includes variables, make sure that they’re defined in your environment or globals. Unresolved request variables can result in invalid server addresses. 

Incorrect protocol: Make sure that you’re not accidentally using https// instead of http:// (or vice versa) in your URL.

Invalid Postman behavior: It’s possible that Postman could be making invalid requests to your server. Check your server logs (if available) to confirm if this is the case.

Very short timeouts: If you configure a very short timeout in Postman, the request may timeout before completion. Try increasing the timeout to avoid this issue and/or set it to zero (0) for infinity

Invalid responses: if your server sends incorrect response encoding errors or invalid headers, Postman won’t be able to interpret the response. 

And of course, if you run into issues that you’re unable to resolve, be sure to file an issue on our GitHub issue tracker. 

Author: Stacee

Product Marketing @ Postman