Consuming Java Web service raises InvalidOperationException

I trying to consume web service from linux/java world.

The code is quite simple:

var client = new ServiceReference.WSService(); 
var response = client.GetData("TEST");

Unfortunatelly I receive InvalidOperationException exception ( XML document contains error - XMlSerializer.Deserialize error). I can successfully consume the same webservice with SoupUI5.

How to find the cause of the error?