Hi Valentina DB Developers,
Very soon (few hours) we will ship release 7.5.
It has some changes in how we working with database file extension.
1) You can read small article about this changes here: http://valentina-db.com/docs/dokuwiki/v7/doku.php?id=valentina:articles:vdb_file_extensions
2) You can read Release Notes of v7.5