Avoiding MC self-signed certificate expiration
When you connect to MC through a client browser, Vertica assigns each HTTPS request a self-signed certificate, which includes a timestamp. To increase security and protect against password replay attacks, the timestamp is valid for several seconds only, after which it expires.
To avoid being blocked out of MC, synchronize time on the hosts in your Vertica cluster, and on the MC host if it resides on a dedicated server. To recover from loss or lack of synchronization, resync system time and the Network Time Protocol.