Woke up this morning to find that my ROCK/NUC system had apparently crashed - could not connect to the Roon Server and the Web Administration page was not accessible.
Could not power off the system using the physical button on the NUC - had to do a hard shutdown by holding it in for 10+ seconds.
The system then powered up OK, and I seem to be back in business.
This has never happened before, so I’m pointing the finger at RoonOS 3.0 in the absence of any other evidence. Perhaps the logs might show something if @support pull them?