using 1.17.0 for TFS 15 receiving the following when a notification attempts to send.
Was working fine in TFS2015 with previous notifcationrelay version, prior to upgrading to TFS 2017

Detailed Message: TfsNotificationRelay: Notify failed for bot hipChat.
Exception Message: One or more errors occurred. (type AggregateException)
Exception Stack Trace:    at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification)    at DevCore.TfsNotificationRelay.HipChat.HipChatNotifier.<>c.<NotifyAsync>b__0_0(Task1 t)
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at DevCore.TfsNotificationRelay.HipChat.HipChatNotifier.d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at DevCore.TfsNotificationRelay.EventHandlers.BaseHandler.d__11.MoveNext()

Inner Exception Details:

Exception Message: An error occurred while sending the request. (type HttpRequestException)
Exception Stack Trace:

Inner Exception Details:

Exception Message: The underlying connection was closed: An unexpected error occurred on a send. (type WebException)Exception Stack Trace:    at System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext& context)
   at System.Net.Http.HttpClientHandler.GetRequestStreamCallback(IAsyncResult ar)

Inner Exception Details:

Exception Message: Authentication failed because the remote party has closed the transport stream. (type IOException)
Exception Stack Trace:    at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
   at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)