Yes, unfortunately, there was a short (approximately 5 minutes) downtime on our servers. We assume that some temporary issue within the datacenter's network caused the downtime. We're currently investigating the issue.
However, right now our servers are up and running. Sorry for the inconvenience.
And now they are back up. This seems different from previous (fairly infrequent) loss of online status for all our hosts as they have been offline for about 20mins for me. Also some can be connected to even though they show offline...
Just for your information; all PC were showed as Offline, but, when I tried to login a targeted PC, it prompted the password and actually I could login it. Then the attempted PC remains Online. Once I closed the Viewer UI and reopened, all PC were showed as Offline again. Thank you.