In short
No site at all: check that the box is on and reachable,
systemctl status warda, journalctl -u warda. One broken site:
"Something is broken". Lost password: sudo warda reset-password NAME.
Diagnostic to send: System → Download a diagnostic (no browsing data).
No site opens on the network any more. The box may be off or unplugged. Check its power and its cable. Meanwhile, set the DNS of the router back to its default: the Internet works again, without protection. If Warda gives the addresses of the network (DHCP), turn the DHCP server of the box on again: the devices keep their address for a day.
One site or one application no longer works. Use Something is broken on that device (chapter 5).
Forgotten password. Another administrator gives you a temporary one
from Accounts. Otherwise, on the box:
sudo warda reset-password YOUR-NAME.
The page of Warda no longer opens. Try http://ADDRESS-OF-THE-BOX
instead of http://warda, from a device on the same network.
Checking the network. Network → Tools gathers small tools run from the box: ping and traceroute (with the country of each router), DNS test (does Warda block this name, and why?), port test (does the box let encrypted DNS through, port 853?), Wake-on-LAN, "who uses this address?" (two machines on the same address) and DHCP test. A device that left the network is never removed: it shows as "Not available", with the last time it was seen.
Asking for help. In System, Download a diagnostic makes a file that describes the state of Warda and its last errors, without any name of a site visited nor any secret: attach it to your request.