Seems there is no way to remove bookmark. Tried Shift-bookmark, and erased the bookmark, then OK, and error comes out. Suggest a "Remove Bookmark" at the end of menu, to go the any of the 10 bookmarks to be removed. Thank you.
Also, when I access a bookmark, the verse reference on the left side of "Toggle Dual Viewer" button, does not show the verse correctly - It remains the same as before I press bookmark to go to another book.