Sometimes Strongbox doesn't completely uninstall when deleted from the MacOS Applications folder (due to an issue with macOS). If you'd like to completely clear all Strongbox preferences/settings then:
- Open Preferences and select Advanced > Factory Reset (at the bottom of the window)
- Delete Strongbox from your Applications folder
- Reinstall Strongbox from the App Store
Terminal Method
For those interested in clearing all the files themseleves, open your favourite Terminal app and enter the following commands:
rm -rf ~/Library/Containers/com.markmcguill.strongbox*
rm -rf ~/Library/Group\ Containers/group.strongbox.mac*