Soliving: Visual Studio 2013 U1 Lightswitch – March 2014–Can’t create project (.lsxtproj) is not supported.
After updating the SQL Server Data Tools in Microsoft Visual Studio 2013, creating a LigthSwitch project will result in an error: ‘…\Application1.lsxtproj’ cannot be opened because its project type (.lsxtproj) is not supported by this