I am using tridion core service in my project(VS 2010 .Net Framework 4.0)
When i update the service reference then its become unknown. its removing all references after updating the tridion core service reference.
Can any one suggest me what am i missing?
Starting with SDL Tridion 2011 SP1, Tridion started shipping a pre-built CoreService client. You can find this dll under [Tridion]\bin\client\Tridion.ContentManager.CoreService.Client.dll.
Other than the usual classes, this also includes some optimizations done to the client. Details on how you could use this assembly are available in the Tridion Practice.