I attempted to log into my TrueNAS Core machine "blue" and discovered I could not login. I got stuck in the process with the page saying:
Connecting to TrueNAS ... Make sure the TrueNAS system is powered on and connected to the network.
When I KVM'ed into the console I was getting a traceback error message. I have attached a screen shot. I don't know what other logs to attempt to collect. I was able to restore access by running:
service middlewared restart