
You should be hitting the "restore database"icon on the upper left (down arrow and a disk icon). That in turn should take you to a default location which may or may not be the location of the database. You'd navigate to the actual location and folder and select ("open"). After that, you'll be prompted to name it and specify a location.
You say "import"; are you doing the above, or something else?
Worst case, you can extract the projects from the existing database backup and paste them into a new database.