If your package opens, but only in the Player, go to Troubleshooting in Asset & Package Viewer. If your package won’t open when you click on it from your Inbox, then check for the following:
Is it expired?
Reach out to the sender of the package if you need more viewing time.
Have you reached the maximum views allowed?
Reach out to the sender of the package if you need more views.
Does the package show (0) files at the end of the package name?
All files have been removed from the package, reach out to the sender to have them re-share a new package. The package may appear to flash to open but immediately will close and is not viewable.