Navision 2016 RTC stop working after login when using public IP address

edwinschutten

I have installed Dynamics Navision 2016 CU67 on a Azure VM (Windows Server 2019 Datacenter).
In SQL Server 2019 I restored a back-up from the Dynamics NAV 2016 application that is running on-premises.

The reason for the new server is that the customer wants to use the NAV 2016 environment as a reference/history environment. They are now working in BC365.

On the server I can login with a local Windows admin account. I have changed the service tier to NavUserPassword and use a thumbprint from a valid certificate.
The server in ClientUserSettings.config is set to local. I can login to the environment.

When I change the server in ClientUserSettings.config to a public IP address or server name, than I can’t login to the environment.
After filling in the username en password, the RTC suddenly stop with an error message in the Event Viewer. I have solved this by entering the server name and public IP address in the hosts file.

But now I have the same problem on my laptop. After login the RTC suddenly stop with the same error message in the Event Viewer. It seems that this happens when I use a public IP address.

When I stop the service tier, than I get the error message “Could not connect to server”. So the port is available.

I have no clue what is going wrong. The error message in the event viewer is:

Event 1026, .NET Runtime

Application: Microsoft.Dynamics.Nav.Client.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.NullReferenceException
at Microsoft.Dynamics.Nav.Client.ConnectionEstablisher.OpenConnectionSystem.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089(Microsoft.Dynamics.Nav.Client.ConnectFailedEventArgs, Microsoft.Dynamics.Nav.Types.ConnectionRequest, Microsoft.Dynamics.Nav.Client.ConnectionOptions, Microsoft.Dynamics.Nav.Client.SpnSetting, Boolean, Microsoft.Dynamics.Nav.Types.UserSettings ByRef)
at Microsoft.Dynamics.Nav.Client.ConnectionEstablisher.OpenConnectionSystem.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089(Microsoft.Dynamics.Nav.Types.ConnectionRequest, Microsoft.Dynamics.Nav.Client.ConnectionOptions, Microsoft.Dynamics.Nav.Types.UserSettings ByRef)
at Microsoft.Dynamics.Nav.Client.ServiceConnection.OpenConnection()
at Microsoft.Dynamics.Nav.Client.ServiceConnection.Initialize()
at Microsoft.Dynamics.Nav.Client.FormBuilder.BuilderSessionInitializer.OpenConnectionToServer()
at Microsoft.Dynamics.Nav.Client.WinClient.NavWinFormsClientSession.OpenServerConnectionCore()
at Microsoft.Dynamics.Nav.Client.WinClient.NavWinFormsClientSession.OpenServerConnectionWithMultipleLoginAttempts()
at Microsoft.Dynamics.Nav.Client.WinClient.NavWinFormsClientSession.InitializeUISession()
at Microsoft.Dynamics.Framework.UI.Windows.ClientSessionBase.InitCore()
at Microsoft.Dynamics.Nav.Client.WinClient.NavWinFormsClientSession.InitCore()
at Microsoft.Dynamics.Framework.UI.ClientSessionCore.Init()
at Microsoft.Dynamics.Framework.UI.Windows.ClientSessionBase.Run()
at Microsoft.Dynamics.Nav.Client.WinClient.NavClientErrorHandler.ExecuteAndCatchExceptions(System.Func`1<Int32>)
at Microsoft.Dynamics.Nav.Client.WinClient.ExceptionHandler.DoExecute(System.Func`1<Int32>)
at Microsoft.Dynamics.Nav.Client.WinClient.StartWinFormsClient.RunCore()
at Microsoft.Dynamics.Nav.Client.WinClient.StartWinFormsClient.Run(Boolean)
at Microsoft.Dynamics.Nav.Client.Program.Main(System.String[])