Thrown when an attempt is made to add an object to the identity cache by using a key that is already being used.
Assembly: System.Data.Linq (in System.Data.Linq.dll)
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.