This error seems to appear on various systems running Exchange Server 2010, when trying to open the Management Console.
It might be caused by one of the latest MS updates.
Connecting to remote server failed with the following error message : The WinRM client received an HTTP server error status (500), but the remote service did not include any other information about the cause of the failure. For more information, see the about_Remote_Troubleshooting Help topic.
Simply install the Windows server’s feature “WinRM IIS extension” (German: WinRM-IIS-Erweiterung).