Exchange 2010 Management Shell will not open.

I recently had a problem on a customer site that had dag in another DR site.So the DR site had one cas/hub server and 2 mailbox servers.

Powershell is crucial for DAG as everything done in the exchange management console is essentially sending through powershell commands.So when I was opening up the exchange management shell i was getting this error.

"Connecting to remote server failed with the following error message: The WinRM client cannot process the request. It cannot determine the content type of the HTTP response from the destination computer. The content type is absent or invalid. For more information, see the about_Remote_Troubleshooting Help topic."

So when i connected to exchange management shell the error message above would display and then the management shell would connect to the cas/hub server.So if I wanted to run any DAG related powershell commands I couldnt because the cas/hub servers didnt have the mailbox role. So i did a lot of research on the internet and tried everything like:

• Running winrm quickconfig
• Adding in the winrm iis listener feature
• Checking iis bindings

I then came across a blog posting whereby adding and removing the wsman and kerbauth modules in the powershell site in iis.So when i clicked on add-module I got the error displayed in the image below.

So to fix it I copied the webconfig file from another mailbox server that had the exchange management shell working fine and replaced the webconfig file on the troublesome mailbox servers and the powershell worked fine.