Persistent Vercel Network Error: Requires Refresh (ERR_CONNECTION_RESET / Invalid Response)

Help
,
1

Hello Community,

I am facing a critical network error on my Next.js App Router application hosted on Vercel. This issue persists despite extensive code-level fixes.

Observed Problem Behavior:

  1. Error Messages: On initial access, the browser consistently throws “The connection for this site is not secure” and “ERR_CONNECTION_RESET” errors.

  2. Consistency: The problem is not isolated to my local network; the error also occurs when accessing the site via cellular data.

  3. Anomaly: The application only loads successfully after 5-7 continuous page refreshes. This suggests the initial attempts are being blocked or reset by the Vercel Edge.

Controls and Code Fixes Applied:

  • Logs: Vercel logs show no deployment errors, and there is no visible error in the domain configuration.

  • MongoDB: Implemented the Global Cache (Connection Pooling) pattern and robust try...catch error handling for database connection. Mongoose timeouts were increased to 15 seconds.

  • Network Evidence: My Vercel CLI outputs showed the “Exceeded query duration limit of 5 minutes” warning during the initial failure attempts.

  • Security: All packages (Next.js 15.5.7, React 19.2.1) are updated to the latest patched versions.

  • Vercel KB Review: I reviewed the article How do I resolve "ERR_SSL_PROTOCOL_ERROR" with Vercel? but the behavior appears less like an ISP block and more like a Serverless/Edge network conflict that resets the connection during the initial cold start response.

Question: Since the application code is robust (it catches DB errors and returns a clean HTML), why is the connection consistently being reset either by the Vercel Edge Network or during the Serverless Function’s initial response? Could this be related to a security policy or an infrastructure conflict on the Vercel side?

Relevant Deployment URL: rsinternationalstudy.vercel.app

5

The issue is not with your app code, ERR_CONNECTION_RESET and ERR_SSL_PROTOCOL_ERROR are issues caused when your browser fails to connect to the server

There can be many reasons for this, from network issues to ISP blocks, but the best way to diagnose is if you run this script which will give us some telemetry about your connection. If you’re currently seeing flaky results that sometimes work, it might be best to run the script a few times in a row and see if you get different outputs

1 Like
6

Hello Jacob,

Thank you for providing the correct PowerShell command. I have successfully run the dedicated vercel-debug.ps1 script now.

Crucial Context (Confirmed Failure Across Networks)

I must emphasize that this issue is not isolated to my home connection. The same “ERR_CONNECTION_RESET” and “ERR_SSL_PROTOCOL_ERROR” behavior persists when accessing the site using multiple different Internet Service Providers (ISPs), including cellular/mobile data. This strongly suggests the issue is related to an infrastructure or filtering policy between the regional ISPs and the Vercel Edge Network, rather than my local settings.

Vercel Debug Script Output

The debug script confirms the network layer issue, showing timeouts and failures during the connection tests:

Host rsinternationalstudy.vercel.app:443 was resolved.

  • IPv6: (none)

  • IPv4: 216.198.79.67, 64.29.17.67

  • Trying 216.198.79.67:443…

  • schannel: disabled automatic use of client certificate

  • ALPN: curl offers http/1.1

  • schannel: next InitializeSecurityContext failed: SEC_E_INVALID_TOKEN (0x80090308) - The token supplied to the function is invalid

  • closing connection #0

Please let me know if you need any other information or logs. Thank you for your help