The database "DatabaseName"\APP_DATA\DatabaseName.MDF' cannot be opened because it is version 661. This server supports version 612 and earlier. A downgrade path is not supported.

The database "DatabaseName"\APP_DATA\DatabaseName.MDF' cannot be opened because it is version 661. This server supports version 612 and earlier. A downgrade path is not supported.
Could not open new database 'D:\DatabaseName\APP_DATA\DatabaseName.MDF'. CREATE DATABASE is aborted.
An attempt to attach an auto-named database for file DatabaseName\App_Data\DatabaseName.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

Ever got this problem? The solution is simple! Do you currently have SQL 2005 installed on your pc? Don't know? Then when you installed Visual Studio 2005 it was installed by default. Uninstall Visual Studio 2005 provided you have either Visual Studio 2010 or 2012. This should solve the problem!!

Happy coding! If  the problem persists let me know!