Preview shows blank screen for PDF docs

Preview is showing a blacked out screen where the document should be.

* MacBook Air (11-inch, Mid 2011)

* upgraded to 10.13.1 within the past week

- behavior did not exist before "upgrade"

- issue limited to PDF's generated by Preview via scan operations

- fwiw the scan ops are via wireless network but i don't think that's the problem

- in Preview "view Thumbnails" and "view Contact Sheet" render thumbs properly

- as file opens you can see the doc image briefly and then it is blacked out once loaded

- files with above behavior open successfully in other apps ( i.e. browser, Adobe Reader )

- files print successfully

- behavior does not occur if I scan in preview and save to jpeg, png or tiff

- older files generated via Preview scans on older versions of OS affected

* this behavior apparently was a known bug in Lion if I remember right

* some folks found relief by deleting .com.apple.Preview.plist ; i did not😟

* no updates show up as available in app store

any ideas?