Afther i try my C# application with QuickOPC License,
when i try to read single node, i obtains this error:

An OPC-UA operation failure with error ID '{359D9885}' occurred, originating from '' and with depth of 1. The inner exception, with error Id "{359D9885}", contains details about the problem.

my code:

....
PS: I have put licensefile .TXT in the application Resource and embedded it,

LicensingManagement.Instance.RegisterManagedResource("QuickOPC", "Multipurpose",Assembly.GetExecutingAssembly(), "*.Key-*.*");
// Instantiate the client object, obtain the serial number from the license info, and display the serial number.
var client = new EasyUAClient();
long serialNumber = (uint)client.LicenseInfo["Multipurpose.SerialNumber"];
// it seem the Serial number in returnde variable serialNumber is good, like 199912345678
.............
.............

I try to read node:

public static bool IsMachineConnectedToNode()
{
// determina se l'OPC della macchina è raggiungibile e leggibile

bool isConnected = true;

UAEndpointDescriptor UaEndpointDescriptor = Vr.OpcServerEndpoint;
UANodeDescriptor UaNodeDescriptor = Vr.OpcServerNode;

try
{
using (var client = new EasyUAClient())
{
var readValue = client.ReadValue(UaEndpointDescriptor, UaNodeDescriptor);

}

}
catch (Exception ex)
{
//Console.WriteLine(ex.Message.ToString());
Fx.WriteLog("!!!--> ERRORE CONNESSIONE MACCHINA: " + ex.Message.ToString());
isConnected = false;
}

return isConnected;
}

Can someone help me please?