Facing issue while sending push notification through the application. The APNs certificate is valid. Below is the error log. System.AggregateException: One or more errors occurred. ---> PushSharp.Apple.ApnsNotificationException: Apns notification error: 'ConnectionError' ---> System.IO.IOException: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host at System.Net.Sockets.Socket.EndSend(IAsyncResult asyncResult) at System.Net.Sockets.NetworkStream.EndWrite(IAsyncResult asyncResult) --- End of inner exception stack trace --- at System.Net.Security._SslStream.EndWrite(IAsyncResult asyncResult) at System.Net.Security.SslStream.EndWrite(IAsyncResult asyncResult) at System.IO.Stream.<>c.b__53_1(Stream stream, IAsyncResult asyncResult) at System.Threading.Tasks.TaskFactory1.FromAsyncTrimPromise1.Complete(TInstance thisRef, Func3 endMethod, IAsyncResult asyncResult, Boolean requiresSynchronization) --- 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 System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) at PushSharp.Apple.ApnsConnection.<SendBatch>d__21.MoveNext() --- End of inner exception stack trace --- at PushSharp.Apple.ApnsServiceConnection.<Send>d__2.MoveNext() --- End of inner exception stack trace --- ---> (Inner Exception #0) PushSharp.Apple.ApnsNotificationException: Apns notification error: 'ConnectionError' ---> System.IO.IOException: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host at System.Net.Sockets.Socket.EndSend(IAsyncResult asyncResult) at System.Net.Sockets.NetworkStream.EndWrite(IAsyncResult asyncResult) --- End of inner exception stack trace --- at System.Net.Security._SslStream.EndWrite(IAsyncResult asyncResult) at System.Net.Security.SslStream.EndWrite(IAsyncResult asyncResult) at System.IO.Stream.<>c.<BeginEndWriteAsync>b__53_1(Stream stream, IAsyncResult asyncResult) at System.Threading.Tasks.TaskFactory1.FromAsyncTrimPromise1.Complete(TInstance thisRef, Func3 endMethod, IAsyncResult asyncResult, Boolean requiresSynchronization) --- 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 System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task) at PushSharp.Apple.ApnsConnection.d__21.MoveNext() --- End of inner exception stack trace --- at PushSharp.Apple.ApnsServiceConnection.d__2.MoveNext()<---