SharePoint 2013 item event receiver not firing while calling web service method

I have created a ItemAdded event receiver in SharePoint 2013 document library using C#, which is working fine for updating text values to fields, But not firing after adding a web service method.

Web Service method is working fine in my web application. sample code is as follows.

ServiceReference1.RestServiceImplClient test = new ServiceReference1.RestServiceImplClient();
                    string s = test.XMLData("1") != null ? test.XMLData("1").ToString() : "Unknown";
                    currentItem["Test"] = s;

Please help me to solve this issue

Thanks in advance