1. General Results, most used to calculate the result A name "98.7.208.50" is ipv4 address, public suffix is not defined A good: All ip addresses are public addresses A good - only one version with Http-Status 200 A Good: Some urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset):1 complete Content-Type - header (2 urls) http://98.7.208.50/ 98.7.208.50 Url with incomplete Content-Type - header - missing charset H fatal error: No https - result with http-status 200, no encryption H Fatal error: http result with http-status 200, no encryption. Add a redirect http ⇒ https, so every connection is secure. Perhaps in your port 80 vHost something like "RewriteEngine on" + "RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,QSA,R=permanent]" (two rows, without the "). Don't add this in your port 443 vHost, that would create a loop. 2. DNS- and NameServer - Checks 3. Content- and Performance-critical Checks A Good: All checks /.well-known/acme-challenge/random-filename without redirects answer with the expected http status 404 - Not Found. Creating a Letsencrypt certificate via http-01 challenge should work. If it doesn't work: Check your vHost configuration (apachectl -S, httpd -S, nginx -T). Every combination of port and ServerName / ServerAlias (Apache) or Server (Nginx) must be unique. Merge duplicated entries in one vHost. If you use an IIS, extensionless files must be allowed in the /.well-known/acme-challenge subdirectory. Create a web.config in that directory. Content: <configuration><system.webServer><staticContent><mimeMap fileExtension="." mimeType="text/plain" /></staticContent></system.webServer></configuration>. If you have a redirect http ⇒ https, that's ok, Letsencrypt follows such redirects to port 80 / 443 (same or other server). There must be a certificate. But the certificate may be expired, self signed or with a not matching domain name. Checking the validation file Letsencrypt ignores such certificate errors. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. A Info: No img element found, no alt attribute checked A Good: Domainname is not on the "Specially Designated Nationals And Blocked Persons List" (SDN). That's an US-list of individuals and companies owned or controlled by, or acting for or on behalf of, targeted countries. It also lists individuals, groups, and entities, such as terrorists and narcotics traffickers designated under programs that are not country-specific. Collectively, such individuals and companies are called "Specially Designated Nationals" or "SDNs." Their assets are blocked and U.S. persons are generally prohibited from dealing with them. So if a domain name is on that list, it's impossible to create a Letsencrypt certificate with that domain name. Check the list manual - https://www.treasury.gov/resource-center/sanctions/sdn-list/pages/default.aspx A Duration: 23997 milliseconds, 23.997 seconds