Yes, Kirk Baker, you have perfectly formulated my problem : when I open a file with PM Plus, the contact sheet appears empty, and I have to click on the popup menu saying "All" to see the images inside the file. The two attached screenshots show the problem. "PM Plus 1.jpg" shows the empty contact sheet that appears when I double click on the file "Paris - Expo Coll. Chtchoukine 2017 lgt", and "PM Plus 2.jpg" shows the contact sheet with images that appears when I have clicked on the button "All" in the toolbar.
Thank you very much for your kind help. Thierrymige