Hi Suzanne, you're posting in the Photoshop Elements forum. The Ps forum is over here but your question seems germane to both so this PSE kb may help. Does your multipage PDF contain both text and images? It probably doesn't matter but I'm curious, when saving did you use the standard "Save" dialog, "Save As...", "Export to PDF", or "Print to PDF", and did you see any options to choose different levels of compatibility? My gut tells me something's amiss with your file but I'm guessing, and it wouldn't be the first time (or last) I barked up the wrong tree. Since I don't know for sure, I'd experiment saving your PDF out in Word by a couple different methods and see if that helped.
I'm having a similar problem with Elements 2019. I open a PDF to select one page of a multi-page document to turn into an image/photo, (which I've done a zillion times), and now it opens to a blank page. Choose PDFClick on page I wantTurns into a blank file