Hi
You imported a video.........Did you save a copy?
Closing the project (effectively shutting down VP) and selecting "Discard" removes all the editing you did. Had you selected "Save" VP would have saved a vpj file which would have enabled you to reload your work. (The video + editing)
As, (presumably) you did not do a "Save Project" or "Save project as" whilst you were editing you won't have anything to fall back on. In effect you will have to start again with the imported video.
How did you import your ScanDisc video into VP without having created a copy first?
Nat