WinRM already is set up to receive requests on this machine.
Message = WinRM cannot process the request. The following error occured while using Negotiate authentication: An unknown security error occurred.
Possible causes are:
-The user name or password specified are invalid.
-Kerberos is used when no authentication method and no user name are specified.
-Kerberos accepts domain user names, but not local user names.
-The Service Principal Name (SPN) for the remote computer name and port does not exist.
-The client and remote computers are in different domains and there is no trust between the two domains.
After checking for the above issues, try the following:
-Check the Event Viewer for events related to authentication.
-Change the authentication method; add the destination computer to the WinRM TrustedHosts configuration setting or use HTTPS transport.
Note that computers in the TrustedHosts list might not be authenticated.
-For more information about WinRM configuration, run the following command: winrm help config.
Error number: -2144108387 0x8033809D
An unknown security error occurred.
Keep in mind what you are doing, opening WinRM via HTTP/HTTPS. Check what your server is configured for (80 or 443, or both) and review the SPN's, and add what is needed.
To review (read only)
setspn.exe -L MACHINENAME
Review the results for HTTP/HTTPS entries (or any duplicates as well)
Add missing names:
setspn -A HTTP/machinename
setspn -A HTTP/machinename.fqdn.com
setspn -A HTTPS/machinename
setspn -A HTTPS/machinename.fqdn.com
They reattempt your quickconfig.