Let's Encrypt certificate could not be issued or renewed with the following error message:
Detail: Invalid response from http://example.com/.well-known/acme-challenge/MANdx2vNFLjJ5yy7cNaV88NiQzddIDU7Gj3bpwTCllA [203.0.113.2]: "<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">rn<html xmlns="http"
SSL It! extension misconfiguration.
Connect to the server via RDP.
Run the following command in command prompt as Administrator to disable SSL It!:
plesk ext sslit --common-challenge-dir -disable
Run the following command to enable it back again:
plesk ext sslit --common-challenge-dir -enable