When trying to open EMS on all CAS Servers, an error is received -
"The WinRM Shell client cannot process the request. The shell handle passed to the WSMan Shell function is not valid. The shell handle is valid only when WSManCreateShell function completes successfully. Change the request including a valid shell handle and try again."
Most people have solved this by going into the bindings of the Exchange Back End site in IIS and assigning a certificate. There is already a certificate assigned, so that is not the problem. We are using a wildcard certificate, but I don't think that is the problem because I have reassigned the default self signed cert as well as creating a new certificate with the FQDN of the server as the CN and it produces the same results.
I am able to "fix" the error by changing the path of "PowerShell" under the Default Web Site in IIS from "C:\Program Files\Microsoft\Exchange Server\V15\FrontEnd\HttpProxy\PowerShell" to "C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\PowerShell", but that is not a good solution as I am sure it can cause other problems.
We are running Exchange 2013 CU5. We have four CAS servers spanning two sites (two in each site) and they are all running Server 2008 R2 Standard. All four CAS servers are having the problem. This is an environment I inherited, so I can't say when the error started happening (after initial installation, applying an update, etc.).
Any help is greatly appreciated!