w3.dmat.ufrr.br has an A (IPv4) record (200.129.159.22) but a request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address.
Get "http://w3.dmat.ufrr.br/.well-known/acme-challenge/letsdebug-test": read tcp 172.104.24.29:59040->200.129.159.22:80: read: connection reset by peer
Trace:
@0ms: Making a request to http://w3.dmat.ufrr.br/.well-known/acme-challenge/letsdebug-test (using initial IP 200.129.159.22)
@0ms: Dialing 200.129.159.22
@321ms: Experienced error: read tcp 172.104.24.29:59040->200.129.159.22:80: read: connection reset by peer
A test authorization for w3.dmat.ufrr.br to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
200.129.159.22: Fetching http://w3.dmat.ufrr.br/.well-known/acme-challenge/Y3tasmIT3nVQcfsfY4GYtiHJJf_eGr37imJX1iBnrC8: Connection reset by peer