IIS Default Site Placeholder host: (detecting…) time: (detecting…)

This virtual host has not been configured yet in IIS Manager.

You’ve reached a server endpoint that is responding, but the site binding or application configuration for this hostname hasn’t been completed.

What this usually means: DNS points here, but the IIS site/binding (or certificate / host header) has not been set up for (this host).

Quick setup checklist (IIS)

  1. 1
    In IIS Manager, create or select the target site and choose Bindings… to add a host header for (hostname).
  2. 2
    Ensure the binding matches the correct IP, port, and (if HTTPS) the correct TLS certificate.
  3. 3
    Confirm the site points to the right physical path, then Start the site or recycle the app pool.
  4. 4
    Re-check DNS (A/AAAA/CNAME) and any reverse proxies / load balancers in front of IIS.