The error is due to the incompatibility of the database you are trying to import as compared to the version of SQL server you are trying to import as destination server.
The error is :
“Database ‘pubs’ cannot be upgraded because its non-release version (539) is not supported by this version of SQL Server.
You cannot open a database that is incompatible with this version of sqlservr.exe. You must re-create the database.
Could not open new database ‘pubs’. CREATE DATABASE is aborted. (Microsoft SQL Server, Error: 950)”
Possible reasons:
Trying to restore an older version of the databases into higher version of SQL Server engine (based on compatibility mode)
Possible Solutions:
- One way is to extract the source database by exporting to SQL script and executing on the destination server
- or use SQL Database Migration wizard. Even though it was created specifically for migration on premise DB to cloud database it works for on premise DB to on premise migration too)

