I’m sorry. I didn’t make myself quite clear.
It’s not that the USB import fails, per se. It’s that when the camera decides to split an uninterrupted sequence into two folders, Fusion Studio treats the two folders as one Multishot sequence, and invariably crashes on the first image in the second folder. The USB interface works just fine. It’s Fusion Studio that vomits.
The reason manually importing works around this is because you can process the folders individually by only placing one set (front and back) at a time in a folder on the computer, and navigating Fusion Studio to that folder.
In other words, either folder pair will render fine on its own. But when Fusion Studio automatically imports them to itself from the camera, it treats the two sequential pairs of folders as one multishot set (presumably because of the EXIF timestamps) and tries to process them sequentially – and crashes on the first image in the second folder. Manually importing the files and processing them individually prevents that from happening because Fusion Studio can’t see the other par of folders in the sequence.
The one thing I am almost certain will cause the camera to split a sequence into multiple folders is a momentary loss (or re-acquisition) of the GPS signal. There may be other reasons, as well. Whatever the case, every time I’ve had Fusion Studio crash at the same image on two consecutive render attempts, the problem was that the camera had split the sequence into two (or more) folders; and every time I processed those folders individually without letting Fusion Studio know that the other folders existed, they processed successfully.
So in summary, the USB interface works just fine. The problem is in the software not being able to handle a sequence that was split into two folders by the camera. If you present the two sets of folders separately, the render will succeed.