When doing a schema compare from a Visual Studio project to a database hosted in SQL Server the following error message appeared:

This error message appeared because I was using SQL Server 2012 in this specific development environment and hadn’t updated the SQL Server Data Tools (SSDT) to the correct version to support SQL Server 2012.

Solution: Upgrade SSDT for Visual Studio to the latest version and update the database project.

Steps

1. Update SSDT
2. Update the Data-Tier Application Framework
3. Update the Project

Visual Studio 2010 (and 2012) Premium and Ultimate support comparison and synchronization of database schemas. this feature is described on MSDN here:

http://msdn.microsoft.com/en-us/library/dd193250(v=vs.100).aspx

More information

Microsoft SQL Server Data Tools …

…provides an integrated environment for database developers to carry out all their database design work for any SQL Server platform (both on and off premise) within Visual Studio. Database developers can use the SQL Server Object Explorer in VS to easily create or edit database objects and data, or execute queries…

http://msdn.microsoft.com/en-us/data/tools.aspx

Download the latest SSDT and Power Tools:

http://msdn.microsoft.com/en-us/data/hh297027

Download the Microsoft® SQL Server® 2012 Data-Tier Application Framework (November 2012)

http://www.microsoft.com/en-us/download/details.aspx?id=35756

How to: Convert VS 2010 Database Projects to SSDT Database Projects and Re-target to a Different Platform

http://msdn.microsoft.com/en-us/library/hh272689(v=vs.103).aspx