One or more of these pages are in use and could not be deleted.
There was a post with this issue marked "solved" (therefore not open to new comments) by updating to the latest version, however I have the latest version and am experiencing the inability to delete pages, given the window "One or more of these pages are in use and could not be deleted". I now must drag them to the end of the document, and when done, split it & discard the file with the unwanted pages, but that is a lot of work with a lengthy document. If I knew what "in use" meant, I could rectify the situation.
Mac 10.9.5, Acrobat Pro 10.1.16

