Post-Install WSUS Configuration Fails With Error “HTTP status 503: Service Unavailable.”

Post-Install WSUS Configuration Fails With Error “HTTP status 503: Service Unavailable.”

I tried to install WSUS role on the one of my new VM, but i got a error on the post-instalation task.

When looking at the produced temp file, it showed the following error:

2018-04-18 18:27:33  CreateDefaultSubscription failed. Exception: System.Net.WebException: The request failed with HTTP status 503: Service Unavailable.
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at Microsoft.UpdateServices.Internal.ApiRemoting.GetServerVersion()
   at Microsoft.UpdateServices.Internal.DatabaseAccess.AdminDataAccessProxy.GetServerVersion()
   at Microsoft.UpdateServices.Internal.BaseApi.UpdateServer.CreateUpdateServer(String serverName, Boolean useSecureConnection, Int32 portNumber)
   at Microsoft.UpdateServices.Internal.BaseApi.UpdateServer..ctor(Boolean bypassApiRemoting)
   at Microsoft.UpdateServices.Setup.StartServer.StartServer.CreateDefaultSubscription()
2018-04-18 18:27:33  StartServer encountered errors. Exception=The request failed with HTTP status 503: Service Unavailable.
2018-04-18 18:27:33  Microsoft.UpdateServices.Administration.CommandException: Failed to start and configure the WSUS service
   at Microsoft.UpdateServices.Administration.PostInstall.Run()
   at Microsoft.UpdateServices.Administration.PostInstall.Execute(String[] arguments)

I tried removing the WSUS role from my VM WS2016 , and reinstalling again again, but without success.

The solution is very simple. 

1. Go to the IIS Console on your WSUS server
2. Delete existung WSUS Administration site
3. Reinitiate the post-instalation task.