Sending an ACME HTTP validation request to rpg.goctionni.net results in an unacceptable redirect. This is most likely a misconfiguration of your web server or your web application.
Bad scheme provided when fetching about:blank: about
Trace:
@0ms: Making a request to http://rpg.goctionni.net/.well-known/acme-challenge/letsdebug-test (using initial IP 2a00:1478:20:0:4::16)
@0ms: Dialing 2a00:1478:20:0:4::16
@166ms: Server response: HTTP 302 Found
@166ms: Received redirect to about:blank
A test authorization for rpg.goctionni.net to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching about:blank: Error getting validation data
rpg.goctionni.net has both AAAA (IPv6) and A (IPv4) records. While they both appear to be accessible on the network, we have detected that they produce differing results when sent an ACME HTTP validation request. This may indicate that the IPv4 and IPv6 addresses may unintentionally point to different servers, which would cause validation to fail.
[Address Type=IPv4,Server=nginx/1.4.6 (Ubuntu),HTTP Status=200] vs [Address Type=IPv6,Server=Apache/2.2.22 (Ubuntu),HTTP Status=302,Number of Redirects=1,Final HTTP Status=302]