Request Failed: Unable to connect to the remote server

All connections are failing in Sonarr.
i get the following detailed error

System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 127.0.0.1:51577
   at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)
   --- End of inner exception stack trace ---
   at System.Net.HttpWebRequest.GetResponse()
   at NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in m:\BuildAgent\work\328d72309b633a8\src\NzbDrone.Common\Http\HttpClient.cs:line 86
   at NzbDrone.Common.Http.HttpClient.Get[T](HttpRequest request) in m:\BuildAgent\work\328d72309b633a8\src\NzbDrone.Common\Http\HttpClient.cs:line 160
   at NzbDrone.Core.Update.UpdatePackageProvider.GetRecentUpdates(String branch) in m:\BuildAgent\work\328d72309b633a8\src\NzbDrone.Core\Update\UpdatePackageProvider.cs:line 46
   at NzbDrone.Core.Update.RecentUpdateProvider.GetRecentUpdatePackages() in m:\BuildAgent\work\328d72309b633a8\src\NzbDrone.Core\Update\RecentUpdateProvider.cs:line 26
   at NzbDrone.Api.Update.UpdateModule.GetRecentUpdates() in m:\BuildAgent\work\328d72309b633a8\src\NzbDrone.Api\Update\UpdateModule.cs:line 21
   at NzbDrone.Api.REST.RestModule`1.<set_GetResourceAll>b__c(Object options) in m:\BuildAgent\work\328d72309b633a8\src\NzbDrone.Api\REST\RestModule.cs:line 111
   at CallSite.Target(Closure , CallSite , Func`2 , Object )
   at Nancy.Routing.Route.<>c__DisplayClass4.<Wrap>b__3(Object parameters, CancellationToken context)

What’s running at that address? Do you have a proxy enabled in IE?

Uhm nothing on that port running, also not a proxy defined in IE.
so its some kind of other proxy/maleware i should be looking for?

For some reason Sonarr is trying to connect through that endpoint to connect to our server (checking for an update). The only other legitimate thing I can think of is a VPN client that runs a proxy, but that seems odd.

Not really sure what you should be on the look out for, but that port doesn’t have to do with Sonarr.