"Certificate is not valid" issue

Looking for advice on solving an issue with deployment on IIS v10:

The “Request Certificate” process ran to success. However, the certificate is not recognized as valid.
(“Certificate is not valid”).


  • the “.well-known/acme-challenge/configcheck” file is accessible from the internet.
  • binding on port 443 looks OK.
  • Certificate Authority is set to “Let’s Encrypt”

It’s working now. Maybe just a cache issue? Or lag time by Certificate Authority?

It’s possible for your computer to see a cert is invalid because your actual computer time is out of sync with internet time, because your certificate appears to start it’s validity some time in the future. Both your server and the computer you are browsing from need to have the correct time and the normal solution for that is to use an internet time server. In windows you can just let windows update it automatically.

The app will warn you if it thinks the server time is out of sync.