Let's Debug

Test result for www.gnaarl.de using http-01

Debug
Requests made to the domain
Request to: www.gnaarl.de/188.68.60.18, Result: [Address Type=IPv4,Server=nginx/1.14.2,HTTP Status=404], Issue:
Trace:
@0ms: Making a request to http://www.gnaarl.de/.well-known/acme-challenge/letsdebug-test (using initial IP 188.68.60.18)
@0ms: Dialing 188.68.60.18
@194ms: Server response: HTTP 404 Not Found

Debug
A and AAAA records found for this domain
www.gnaarl.de. 0 IN A 188.68.60.18
Challenge update failures for www.gnaarl.de in order https://acme-staging-v02.api.letsencrypt.org/acme/order/5751349/18966722
acme: error code 403 "urn:ietf:params:acme:error:unauthorized": Invalid response from http://www.gnaarl.de/.well-known/acme-challenge/_dOOGTvHZmm2mJuBH-aYTiWazKhs2CzX8LrNhxNVjOs: "<html>\r\n<head><title>404 Not Found</title></head>\r\n<body bgcolor=\"white\">\r\n<center><h1>404 Not Found</h1></center>\r\n<hr><center>"
Debug
The IANA public suffix is the TLD of the Registered Domain
The TLD for www.gnaarl.de is: de
Debug
The current status.io status for Let's Encrypt
Operational

Submitted Jan 8 12:12:05 2019. Sat in queue for 3ms. Completed in 9s. Hide verbose information.