Hopefully someone can help me here. I'm running El Capitan on an iMac and for some reason I cannot import any of my video files. I had a problem recently when VIRB Edit refused to load at all. I deleted everything on the Mac related to it, reinstalled it and now it will open however when I try and import the videos it won't do it. It looks as though it's importing them but when it's finished there's nothing there. I can't drag and drop them either.
Take a look in your "~/Library/Application Support/Garmin/VIRB Edit/Database/1/RawMovies/" folder. The "Library" folder is a hidden folder, so you'll need to use the "Go > Go to Folder..." menu item to access it. When you import a video, a new folder should be created there with the data about the imported video. If it's not appearing there, or you can't get to the folder, there may be a permissions issue preventing VIRB Edit from writing data there.
Another thing to look at, when you removed VIRB Edit the first time, did you delete the preferences plist in ~/Library/Preferences as well?