Ok, the next bug after upgrading from VMware vCenter Server 5.5 to vSphere 6.0 Update 2, great.
When I try to search for virtual machines with the vSphere Client 6, the following error occures and the search fails:
The server could not interpret the communication from the client. (The remote server returned an error: (500) Internal Server Error
This only happens when I use the checkbox “Use Windows session credentials” during login to the vSphere Client. If I uncheck the box and type in the necessary credentials, everything works fine. By the way, the error does not occure when using the Webclient.
There is a VMware KB describing this situation. It is a known issue affecting vCenter Server and vCenter Server Appliance. According to the KB the issue already exists since vCenter Server Appliance Version 5.0.x.