An alarm is seen in the NSX-T UI citing that a certificate is expired. The Alarm resembles the screenshot below:
In the Syslog (var/log/syslog) of an NSX T Manager, one can also find an correlated error resembling that of below:
2022-01-17T10:06:09.706Z manager1 NSX 5443 MONITORING [nsx@6876 alarmId="<UUID>" alarmState="OPEN" comp="nsx-manager" entId="<UUID>" errorCode="MP701099" eventFeatureName="certificates" eventSev="CRITICAL" eventState="On" eventType="certificate_expired" level="FATAL" nodeId="<UUID>" subcomp="monitoring"] Certificate <UUID> has expired.
Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.
VMware NSX-T Data Center 3.x
VMware NSX