I open a document, and view thumbnails. I go to Edit > Insert > Page From Scanner / Page From File / Blank Page - but these three options are not highlighted so I can not choose them. This always worked in the past! can't figure out why it won't let me select any of them... I also tried dragging and dropping pages into the thumbnails and it seems to work but when I save the document and then close and reopen it, only the first page shows up and all the other pages are gone. Please help me!!!