I am using a Canon Vivia HF R500 to take videos and downloading them to my iPad Air 2 via a USB to Lightening connection. This has been working flawlessly for me for months. I open Photos, connect the camera, and an import icon shows up. I select the videos I want, and click import. Then the videos show up in Albums > Videos.
Today it stopped working. The iPad sees the camera, shows the import icon, lets me select the videos, and seems to import them, but they never show up on the iPad. When I try to import them again, it gives the error message
Duplicate Photos: All of these photos already exist in your Photo Library.
The videos do not exist on any of my devices or iCloud through the web. What can I do?
I've installed iFunBox to try and locate them (or the problem) via the iPad file system, but am not familiar enough with it to make changes.