1. General Results, most used to calculate the result A name "y21.xyz" is domain, public suffix is "xyz", top-level-domain-type is "generic", tld-manager is "XYZ.COM LLC" A Good: All ip addresses are public addresses A Good: No asked Authoritative Name Server had a timeout A Good - only one version with Http-Status 200 HSTS-Preload-Status: unknown. Domain never included in the Preload-list. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. A Good: Some urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset):0 complete Content-Type - header (4 urls) http://y21.xyz/ 139.59.84.48 Url with incomplete Content-Type - header - missing charset http://www.y21.xyz/ 139.59.84.48 Url with incomplete Content-Type - header - missing charset http://y21.xyz/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 139.59.84.48 Url with incomplete Content-Type - header - missing charset http://www.y21.xyz/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 139.59.84.48 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. M http://www.y21.xyz/ 139.59.84.48 Misconfiguration - main pages should never send http status 400 - 499 2. Header-Checks 3. DNS- and NameServer - Checks A Good: Consistency between delegation and zone. The set of NS records served by the authoritative name servers must match those proposed for the delegation in the parent zone. Ordered list of name servers: ns1.digitalocean.com,ns2.digitalocean.com,ns3.digitalocean.com A Good: Nameserver supports TCP connections: 6 good Nameserver A Good: Nameserver supports Echo Capitalization: 6 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 6 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 6 good Nameserver A Good: All SOA have the same Serial Number Warning: No CAA entry with issue/issuewild found, every CAA can create a certificate. Read https://en.wikipedia.org/wiki/DNS_Certification_Authority_Authorization to learn some basics about the idea of CAA. Your name server must support such an entry. Not all dns providers support CAA entries. 4. 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 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: 26854 milliseconds, 26.854 seconds