Totally black preview images

I'm trying to download some preview images for comping and approval by the client before purchase. I have tried two ways, download to desktop and through the library. They appear fine in the icons in the library, but as soon as I drag them into the document they are just a black square with the Adobe logo across the middle, which is of course completely useless. Am I missing something obvious? Never had this happen before on any other stock sites (or on Adobe Stock for that matter), but I'm kind of still stuck with Adobe Stock at the moment after being kidnapped and taken hostage from Dollar Photo Club.