I\'ve got a database project as part of my solution in Visual Studio 2013. Been working perfectly for the last 3 weeks and now suddenly today it won\'t build and so I cannot
I had the same issue and just restart the Visual Studio and it works for me.
You need to install the last version of SQL Server Data Tools:
http://msdn.microsoft.com/en-US/data/hh297027
Make sure to restart VS and then build the solution again. This solves the problem!
In Visual Studio 2013 -> Tools -> Extensions and Updates... -> Updates -> Product Updates -> Microsoft SQL Server Update for database to 12.0.50318.0
I was upgrading from 12.0.41012.0 and this resolved my issue. This relates to the answer to install the latest SQL Server Data Tools.