I have just recently replaced an old WatchGuard XTM300 with a new WatchGuard M200 firewall at one of our facilities. Immediately after the switch we noticed that the SSLVPN connections were failing. In the client log files we found the error “Failed to get domain name.” After a bit of detective work we found that the certificates used by the SSLVPN were stuck in the state “Pending.”
To resolve the issue we deleted the stuck certificates and rebooted the firewall. Once the firewall has rebooted, the certificates should be re-issued and have a status of “Signed”.