PROBLEM

When you install VMware vSphere Client on Windows Server 2008 R2 64-bit, the client may not run and you will receive the following errors when attempting to launch the client:

Could Not Connect
Error parsing the server “<vCenterServerHostname>” “clients.xml” file.
Login will continue, contact your system administrator.

You click OK and then get another error:

Error
The type initializer for ‘VirtualInfrastructure.Utils.HttpWebRequestProxy’ threw and exception.

You click OK and then the vSphere client hangs or crashes.

SOLUTION

To resolve this issue, perform the following:

1. Obtain a copy of the %SystemRoot%\Microsoft.NET\Framework\v2.0.50727\System.dll file from a non Server 2008 R2 (or non-Windows 7) machine that has .NET 3.5 SP1 installed. (I took mine from my 32-bit Windows XP SP3 machine)
2. On the Windows Server 2008 R2 machine where the vSphere client is installed, create a folder called “Lib” under the vSphere Client ‘Launcher’ directory. For example: C:\Program Files (x86)\VMware\Infrastructure\Virtual Infrastructure Client\Launcher\Lib
3. Copy the System.dll file from Step 1 into the C:\Program Files (x86)\VMware\Infrastructure\Virtual Infrastructure Client\Launcher\Lib directory
4. In the vSphere client launcher directory, open the VpxClient.exe.config file in a text editor and modify the file as follows:<?xml version=”1.0″ encoding=”utf-8″?>
   <configuration>
   <system.net>
   <connectionManagement>
   <clear/>
   <add address=”*” maxconnection=”8″ />
   </connectionManagement>
   </system.net>
   <appSettings>
   <add key = “protocolports” value = “https:443″/>
   </appSettings>
   <runtime>
   <developmentMode developerInstallation=”true”/>
   </runtime>
   </configuration>
5. Create a batch file (e.g. vSphere.cmd) in a location of your choice with the following:
   SET DEVPATH=%ProgramFiles(x86)%\VMware\Infrastructure\Virtual Infrastructure Client\Launcher\Lib
   “%ProgramFiles(x86)%\VMware\Infrastructure\Virtual Infrastructure Client\Launcher\VpxClient.exe”
6. (Optional) Replace the shortcut on the start menu to point to the batch file created in Step 6. Change the shortcut properties to run minimized so that the command window is not shown.

You can now use the VpxClient.cmd (or the shortcut) to launch the vSphere client in Windows Server 2008 R2.

These instructions should also work for running vSphere client on Windows 7.