I logged into my lab vCenter instance today and found this lovely message.
I already made sure the clock was good and even went as far as rebuilding the inventory DB which restarts all the services, but neither made a difference.
vpxd service will be down.
on the appliance please run
service-control --status vpxd
please check vpxd logs.
if you are confident try to srart the vpxd service
service-control --start vpxd
Please mark helpful or correct if my answer resolved your issue.
I took a look at the link for re-registering the PSC but all I could find on it is for when you have the PSC separate from vCenter. In my lab they're all running on the same VM.