Library references keeps disappearing

I have a WCF library project that I referenc开发者_开发问答e from a console app. The problem is every time I add the reference and it registers, it disappears in all of the following cases:

• If I rebuild either project
• If I try to run the console app

Wrong target framework?

Go to your application's properties, click on the Compile tab and set the "Target framework (all configurations):" dropdown from ".NET Framework 4 Client Profile" to ".NET Framework 4"

See also:

Visual Studio 2010 is Eating My DLLs! - referenced third party dlls missing after build

and:

http://msdn.microsoft.com/en-us/library/cc656912.aspx

If you are targeting the .NET Framework 4 Client Profile, you cannot reference an assembly that is not in the .NET Framework 4 Client Profile. Instead you must target the .NET Framework 4. [...]

Features Not Included in the .NET Framework Client Profile

The .NET Framework 4 Client Profile does not include the following features. You must install the .NET Framework 4 to use these features in your application:

ASP.NET

Advanced Windows Communication Foundation (WCF) functionality

.NET Framework Data Provider for Oracle

MSBuild for compiling