Database version is higher than SSMS and throwing error when attempted to create table
AS MSDN Blog Here  Use the SSMS version designed for your database version. You can use the command select @@version; to check which version of SQL Server you are actually using.  Update your SSMS to the latest version and try.  You may have the latest version of SQL Server and older version of SSMS.

To Download the latest SQL Server Management Studio (SSMS) https://msdn.microsoft.com/en-us/library/mt238290.aspx

For your further ref https://stackoverflow.com/questions/25146474/the-backend-version-is-not-supported-to-design-database-diagrams-or-tables