Let's Debug

Test result for klimapartner.de using http-01

klimapartner.de has an AAAA (IPv6) record (2001:8d8:884:c500::44:7dd8) but a test request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address. You should either ensure that validation requests to this domain succeed over IPv6, or remove its AAAA record.
Get http://klimapartner.de/.well-known/acme-challenge/letsdebug-test: dial tcp [2001:8d8:884:c500::44:7dd8]:80: connect: connection refused

Trace:
@0ms: Making a request to http://klimapartner.de/.well-known/acme-challenge/letsdebug-test (using initial IP 2001:8d8:884:c500::44:7dd8)
@0ms: Dialing 2001:8d8:884:c500::44:7dd8
@1106ms: Experienced error: dial tcp [2001:8d8:884:c500::44:7dd8]:80: connect: connection refused
A test authorization for klimapartner.de to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching https://klimapartner.de/.well-known/acme-challenge/2pALw6xoV4TxXY7JKdsRwUMGf8Igw3_whheN-JlF8z4: Connection refused

Submitted Mar 20 12:27:54 2019. Sat in queue for 2ms. Completed in 7s. Show verbose information.