Yesterday we suddenly had issues with opening the Exchange EMC of EMS on one of our Exchange servers.
The exact error is shown below:
“The attempt to connect to http://serverfqdn/powershell using “kerberos” authentication failed: 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.”
Googling this error did not find a proper solution for me.
But, it had something to do with WinRM.
There is a application log specifically for WinRM.
Within the eventlog I found the error below:
”WSMan operation Invoke failed, error code 2150858999”
This error found me a solution!
Changing the values of the MaxResuestBytes en MaxFieldLength registry keys did the trick.
The max value for MaxFieldLength is 65534 ( decimal ) and the max value for MaxRequestBytes is 40000 ( decimal ).
In my case the MaxFieldLength was already set to the maximum, but the MaxRequestBytes was set to 20000.
I changed this value to 40000 and rebooted the server, afterwards I could access the EMC / EMS without any issues.