It does happen some times. In my case it is the vSphere Client in your case it could be vCenter.
You can get onto the host via SSH but the stupid Client gets an error of some sort.
What now?
Reboot the whole damm machine?
No.
It is just a Service as most of anything on the machine. So let us restart the Service.
Using the DCUI for those of you who like it pretty. Getting into the DCUI via SSH ist just the same as running to the machine and doing it right there. Who knows, thge machine mightnot be in reach, so let’s be lazy and stay seated.
Open ssh and connect to the machine (you did enable ssh after installing it initially, right?).
Type: dcui
There you go. Press F2 and log in as root. You are looging for „Restart Management Services“ if you do not se it right away, check if you got „Troubleshooting Options“ … you will find it there.
Now restart.
You can also do all that directly from the console following the VM Ware Instructions.