There are a few things you can check:
- Make sure you have installed Sookasa.
- See if you're logged in to the Sookasa application. You can check by right-clicking (control-click on Mac) the Sookasa icon in your computer’s menu bar or system tray. Choose Preferences, and switch over to Account. It will give you the opportunity to log in if you aren't already.
- Check that you have been authorized to open the Sookasa file by the person who encrypted it.
- See whether Dropbox has been installed to a location that is not the default drive (usually the C: drive). If it isn't, this can cause problems in accessing Sookasa files. To get around this, you can unhide the Sookasa drive by right-clicking the Sookasa icon, select Preferences, and uncheck "Hide Sookasa Drive."