We don't use the appliance.
In our testlab we found a workaround. It looks like a config fault/bug in the Tomcat configuration. The space in the default installation path "c:\program files\vmware\infrastructure" is possibly causing this issue. I found the workaround after finding the following error in the vsphere_client_virgo.log.
Error processed default web.xml named conf/web.xml at C:\Program Files\VMware\Infrastructure\vSphereWebClient\server\conf\web.xml java.net.URISyntaxException: Illegal character in path at index 16:
After installing the Web Client in e.g. "c:\temp" and the Web client is working. The opposite of what is described in kb204495.
I'm still looking for a solution in stead of this workaround.