If you import some images in PureRef, save the scene, delete the original files (the images from disk so they are available only in the .pur scene), export Selected Images from PureRef to desktop and then you try to import those exported images in Photoshop, you'll get (I get this):
Could not complete your request because the file-format module cannot parse the file.
So the files somehow corrupts, is there a solution? I guess it's a bug.
(Export Cropping: Disabled; No Override Name)
Try those files: https://goo.gl/FuEibB