"Loading Assets" unable to import

Working with Arerture 3.4.5

I'm trying to import from a CF card, and while all 1355 jpeg thumbnails are loaidng snappily, I can't start importing them, as I'm stuck on "loading assets" and never unstuck.

I've tried shutting down, rebooting, a different usb port, etc... Sometimes it will show the ImportCHECKED BUTTON AS CLICKABLE, SOMETIMES IT WILL NOT.

What's going on?