Update page in vSphere client shows: "An unexpected error has occurred."

[rpmoyer93]

I am currently managing a vSphere environment with three clusters comprised of 14 hosts with 185 VMs.  On one of my VMs, when you go to the updates screen for VMware tools and HW it shows  "An unexpected error has occurred."  This then also affects when I try to view the clusters status.

[MERBAGRolf]

Exactly the same issues on my site, this somehow seems to be related to the HTML5 interface - in the "old" Flex interface it is always working.

Also this is kinda random since from time to time it is working, sometimes it does not work for the cluster, sometimes not for a host, sometimes not for a VM..

It is only happening when navigation to "Updates - VMWare Tools" - no problem for Hardware nor Host Updates.