To sunshinydays comment, there is nothing in Unsorted Bookmarks.

To idrin's comment, I already have the version you mentioned.

Any more ideas?

I've returned to Opera after a long absence. I used the import feature to get my bookmarks from Firefox. I got a message that the import was successful, but there is nothing at all in the bookmarks display. Are they there but I just don't know how to find them? Any other explanations?