It seems that the VSAN Health Plugin could break the vCenter webclient if it’s not installed correctly. After installing the MSI-Packge on the Windows vCenter server and logging in via the web client everything seemed ok at the begining, but after selectin the datacenter, a cluster or a host/vm the middle section whoich sould display dietalled informatons about the selected property did not load and stayed blank.

After some searching I found an interssting VMware KB-article which described my problem. My vCenter looked like the screenshoot in the below article.

https://communities.vmware.com/thread/510468?start=0&tstart=0

It seems that I made the mistake and installed the VSAN health plugin as a domain admin – and that just does not work.  After uninstalling the plugin, restarting the vCenter, logging in as a local admin, starting a command prompt with admin priviliged and restarting the installation again, it woked fine.

BTW. in the new VSAN health plugin releases VMware fixed the DRS-dependency and now its possible to also install the plugin without activated DRS.  

Before you had to install the Plugin while your system had the evaluation licens where you could activate DRS. If you use a license like  Essentials Plus + VSAN that could be a real problem.