Folder looks empty, but it contains videos

Merceq deliberately doesn’t look inside some locations:

• Photos libraries (.photoslibrary).
• Final Cut Pro libraries (.fcpbundle) and iMovie libraries (.imovielibrary).
• App packages (.app).

To import videos from these locations, first export them from the relevant app to a regular folder. Don’t try to extract videos by changing the internal structure of an app library in Finder.

Files in iCloud that haven’t been downloaded to your Mac aren’t imported either. The import summary says “These files are in iCloud and haven’t been downloaded to your Mac. Download them in Finder and import again.” Download the files in Finder, then import them again.