The operating system or browser does not recognize the local certificate authority (CA) used to sign the localhost certificate.
Error 1: "Your connection is not private" (NET::ERR_CERT_AUTHORITY_INVALID)
: Set your Docker containers to restart: always or restart: unless-stopped in your compose files to ensure they boot with your machine.
While port numbers above 1024 are technically "registered" or "dynamic" and can be used by any developer, port 11501 is most frequently associated with specific developer tools and system services: 1. Microsoft Visual Studio and .NET Core (Kestrel) https localhost11501 2021
: When spinning up complex microservice architectures, .NET dynamically assigns high-range ports. Port 11501 is frequently configured as the secure secondary backend API target.
In modern web development, many frameworks randomly assign high-numbered ports (like 11500–11599) for running local servers. The prefix https:// indicates that the browser expects a secure connection encrypted via Transport Layer Security (TLS).
Configure your server’s routing. For Express: app.use('/2021', express.static('path/to/2021-folder')) . For Python: create a subdirectory named 2021 with an index.html inside. The operating system or browser does not recognize
Firewall and Antivirus BlockingSecurity software often views high-port local traffic as suspicious. If you are in a corporate environment, your IT department may need to whitelist port 11501 to allow the application to communicate properly. The Importance of Port 11501 in 2021
mkcert is a simple tool that creates a local CA on your machine and trusts it automatically in your system's root store. :
Always check what’s actually running on your machine. Use curl -vk https://localhost:11501/2021 to see the raw response (or error) from the command line. This bypasses browser caching and service worker interference. Microsoft Visual Studio and
Third, indicates that the local connection is using Hypertext Transfer Protocol Secure, which means the data exchanged is encrypted. While unusual to see on a local development server, there are reasons to use it, such as testing features that are strictly required to run over HTTPS or replicating the production environment for accurate testing.
What (e.g., .NET, Node.js, Dynamics 365) are you running?
: Paste chrome://flags/#allow-insecure-localhost into your Chrome address bar, switch the toggle to Enabled , and relaunch your browser. This permanently allows unencrypted or self-signed certificates on any localhost port. Summary of Best Practices Recommended Tool Local CA Encryption Safely eliminates browser warnings permanently. mkcert Temporary Bypass Quick testing without modifying server files. thisisunsafe keyboard bypass Port Management Ensures port 11501 is free and not conflicted. netstat -ano (Windows) / lsof -i :11501 (Mac)
Using https:// on localhost indicates the developer attempted to enable . This became more common after 2020 due to: