Before restoring from a full backup, the store files (by default the .iq files) must be removed from the directory to which you are restoring. The sixth bullet in “Data Backup, Recovery, and Archiving > Restoring your databases > Before you restore” should be replaced with:
For a full restore, the store files (by default the .iq files), the catalog store (by default the .db file), and the transaction log (by default the .log file) must not exist in the location to which you are restoring. If any of these files exist, you must delete them or move them to a different directory before doing the full restore.