Document created on iOS won't open on Mac

Purchased the iOS version (and love it), and created a new project on my iPad, synced it via Dropbox. When I tried to open the project on my Mac (which I’d updated to Scrivener version 2.8) to work on it there, I was unable to do so. Here’s the error message (with personal info removed):

(1) How can it be an older format when I just created it in the new iOS app today?
(2) I do not see ‘binder.scrivproj’ in the package contents. Not sure how I would restore from a backup a new file created on iOS.

Advice? Thanks.

Problem solved–here’s what happened, for the benefit of anyone else who sees a similar message. Although I had clicked the update from the menu on the desktop version, and saw a download bar and the app relaunched, it did not in fact install 2.8. (Didn’t think to double-check version at first, since I’d been through the rigmarole of download progress bar, app relaunch. Finally noticed when I tried to go the other way–open a Mac file on iOS.) Went back and downloaded and installed manually from the website, and all is now well.