1. General Results, most used to calculate the result A name "artifactory.acn.miecc.us" is subdomain, public suffix is "us", top-level-domain-type is "country-code", Country is United States of America (the), tld-manager is "NeuStar, Inc." A good: All ip addresses are public addresses A good: No asked Authoritative Name Server had a timeout A DNS: "Name Error" means: No www-dns-entry defined. This isn't a problem A good: destination is https A good - only one version with Http-Status 200 A good: one preferred version: non-www is preferred A good: every https has a Strict Transport Security Header A good: HSTS max-age is long enough, 31536000 seconds = 365 days 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 (2 urls) https://artifactory.acn.miecc.us/ 3.228.23.74 Url with incomplete Content-Type - header - missing charset https://artifactory.acn.miecc.us/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de Url with incomplete Content-Type - header - missing charset A http://artifactory.acn.miecc.us/ 3.228.23.74 https://artifactory.acn.miecc.us/ correct redirect http - https with the same domain name 2. DNS- and NameServer - Checks A Good: Nameserver supports TCP connections: 2 good Nameserver A Good: Nameserver supports Echo Capitalization: 2 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 2 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 2 good Nameserver Nameserver doesn't pass all EDNS-Checks: ns-1924.awsdns-48.co.uk: OP100: no result. FLAGS: no result. V1: no result. V1OP100: no result. V1FLAGS: no result. DNSSEC: no result. V1DNSSEC: no result. NSID: no result. COOKIE: no result. CLIENTSUBNET: no result. 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. 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. https://artifactory.acn.miecc.us/ 3.228.23.74 Warning: https result with status 200 and size greater then 1024 Bytes without GZip found. Add GZip support so the html content is compressed. A Good: No https + http status 200 with inline CSS / JavaScript found A Good: Every https result with status 200 has a minified Html-Content with a quota lower then 110 %. A Good: Every https connection via port 443 supports the http/2 protocol via ALPN. 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 https://artifactory.acn.miecc.us/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 3.640 seconds Warning: 404 needs more then one second A Duration: 47006 milliseconds, 47.006 seconds