Postman could not get any response

The documented message

Postman's official troubleshooting article shows this historical UI wording:

Could not get any response

Message not reproduced in Postman here. Current versions may show more specific connection errors. Open the Console and preserve the actual error from your run instead of assuming the title identifies the cause.

1. The resolved URL or local server is wrong

Check the final scheme, host and port in the Console, including substituted variables. A variable pointing at the wrong environment can make a good collection fail. On the machine sending the request, try the same resolved destination.

This local Node fixture was run, and the curl command returned API lab OK. Save it as api-lab.cjs and run node api-lab.cjs in one terminal; run curl in another.

const http = require('node:http');
http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/plain' });
  res.end('API lab OK\n');
}).listen(4313, '127.0.0.1');

curl -i --max-time 5 http://127.0.0.1:4313/

Use that URL for a manual Postman check. A cloud agent's localhost is not your laptop's localhost; choose a request-sending agent that can reach the API.

2. A proxy, VPN or firewall changes the route

Compare the destination and proxy shown in the Console with the working client's settings. Check with the environment owner whether the endpoint needs VPN or an approved proxy. Repair that route; changing the request body does not fix a connection that never reaches the server.

3. HTTPS verification or client authentication fails

Read the certificate-specific Console message. A custom CA belongs in the CA trust configuration; an mTLS client identity belongs in client certificate configuration. Those solve different problems. See Postman self-signed certificates.

4. The server hangs or returns malformed data

Correlate request time with server logs. A slow upstream and an invalid response require different fixes; increase the request timeout only for a legitimately longer operation. Avoid blind retries of payment-creation requests because a lost response does not prove no payment was created.

Prevention and interview answer

Keep environment URLs explicit and capture a redacted Console error, timestamp and server correlation ID. “I separate transport failure from an HTTP error, then verify destination, route and TLS before examining application assertions.”

A successful curl request does not prove browser cross-origin access; see CORS errors.