The server "DynamicsNAV80" was unable to process the request. The application will close.

When try to login into NAV system, after entry username and password the system raises an error like this below :

The server "DynamicsNAV80" was unable to process the request. The application will close.

 I am confused what it is about ?

I am using Window 10 SL, It has nothing to deal with the operating system. NAV runs well on every type of windows operating system.

If  exprienced an error like this, open the Event Viewer and open the Application Log and search for the nav error.  Below is an example of the log :

Type: Microsoft.Dynamics.Nav.Client.NavClientClosingException
Fatal: False
ShowError: True
Message: The server "DynamicsNAV80" was unable to process the request. The application will close.
StackTrace:
     at Microsoft.Dynamics.Nav.Client.WinClient.ExceptionHandler.DoExecute(Func`1 execute)
     at Microsoft.Dynamics.Nav.Client.WinClient.StartWinFormsClient.RunCore()
Source: Microsoft.Dynamics.Nav.Client.WinClient
HResult: -2146233088
----------------------------------
Type: Microsoft.Dynamics.Nav.Types.Exceptions.NavServerSessionException
Message: The server "DynamicsNAV80" was unable to process the request. The application will close.
StackTrace:
     at Microsoft.Dynamics.Nav.Client.ConnectionStateManager.CallServer[T](BeginCallServerMethod beginCallServerMethod, EndCallServerMethod`1 endCallServerMethod, ServerCallOptions options)
     at Microsoft.Dynamics.Nav.Client.ConnectionStateManager.CallServer[T](BeginCallServerMethod beginCallServerMethod, EndCallServerMethod`1 endCallServerMethod)
     at Microsoft.Dynamics.Nav.Client.ServerInvocationHandler.CallServer[T](BeginCallServerMethod beginCallServerMethod, EndCallServerMethod`1 endCallServerMethod)
     at Microsoft.Dynamics.Nav.Client.ServiceConnection.CallServer[T](BeginCallServerMethod beginCallServerMethod, EndCallServerMethod`1 endCallServerMethod)
     at Microsoft.Dynamics.Nav.Client.ServiceConnection.SetClientSettings(SessionSettings sessionSettings, Boolean saveOnly)
     at Microsoft.Dynamics.Nav.Client.ServiceConnection.SetupCultureCore(SessionSettings sessionSettings, CultureInfo userCulture)
     at Microsoft.Dynamics.Nav.Client.ServiceConnection.SetupCulture(CultureInfo currentCulture)
     at Microsoft.Dynamics.Nav.Client.ServiceConnection.Initialize()
     at Microsoft.Dynamics.Nav.Client.FormBuilder.BuilderSessionInitializer.InitializeService(IService service)
     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.SetupSessions()
     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(Func`1 execute)
Source: Microsoft.Dynamics.Nav.Client.ServiceConnection
HResult: -2146233088
----------------------------------
Type: Microsoft.Dynamics.Nav.Types.Exceptions.NavServerSessionException
Message: The server "DynamicsNAV80" was unable to process the request. The application will close.
HResult: -2146233088
----------------------------------
Type: System.Globalization.CultureNotFoundException
InvalidCultureId: 14345
Message:
  Culture is not supported.
  Parameter name: culture
  14345 (0x3809) is an invalid culture identifier.
ParamName: culture
StackTrace:
     at System.Globalization.CultureData.GetCultureData(Int32 culture, Boolean bUseUserOverride)
     at System.Globalization.CultureInfo.InitializeFromCultureId(Int32 culture, Boolean useUserOverride)
     at Microsoft.Dynamics.Nav.Runtime.NavSession.GetFormattingCulture(ClientSettings clientFormats)
     at Microsoft.Dynamics.Nav.Runtime.NavSession.set_RegionalSettings(ClientSettings value)
     at Microsoft.Dynamics.Nav.Service.NSService.SetClientSettings(SessionSettings settings, Boolean saveOnly)
     at SyncInvokeSetClientSettings(Object , Object[] , Object[] )
     at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
     at Microsoft.Dynamics.Nav.Service.ServiceOperationInvoker.ErrorMappingCombinator(ServiceOperation innerOperation, NSServiceBase serviceInstance, Object[] inputs, Object[]& outputs)
Source: mscorlib
HResult: -2147024809

From the log, it is said that "Type: System.Globalization.CultureNotFoundException"  . The caused of this error is due to the language setting is set to "English (Indonesia)".

When I set the language to "English (United States)" the problem gone.