This means the tncs process experienced a severe issue and had to be restarted. The tncs process (Trusted Network Computing Service) is responsible for the server side of Host Checking. Most likely you will find a stack trace in the event logs at the time of the failure. Depending on the failure type it might affect or not the entire service, or only a few users. In case of TNCS, it is likely Host Checks will have fail or being delayed for those users trying to connect while the TNCS service was restarted.
For this kind of issue, please go ahead and open a JTAC case with the following information:
- all logs (event, admin, access) : Log/Monitoring then click "Save all logs"
- check under Troubleshooting > System Snapshot. If there is a "Process snapshot for tncs" download it from the SA
- on the same page, check the boxes "Include system config", "Include debug logs" anc click on "Take snapshot". This will create another file called "Admin generated snapshot (with debuglog, config), download it as well.