I wanted to add on to the most recent info by NunoAlex. I run OPNsense and ran into the same issue until I changed one setting in Interfaces > [LAN] > IPv6 Configuration Type to DHCPv6. Then I pressed CTRL+C as he had with the stuck installer and it came back to life! Not sure if this is going to have any other side effects yet, but for now, this works. Hope it helps!