exchange and dinamics

Question

dinamics and exchange connection stopped working. account is working, if you log in via web, everything works, the service is created. But with dinamics there is an error -

Inner Exception: System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.   

at System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)   

at System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)Inner Exception: System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host 

There are no entries in the excnahge logs at all, neither in V15\Logging\Ews nor inetpub\logs\LogFiles\W3SVC1.

it's just a server connection error, that's all.