Something just changed, with Dropbox, and I'm frustrated. For months I send csv file to Dropbox, then open in my routing app. Now the app says cannot open the file, (even tried old file that worked), and cannot. When I click on it in Dropbox, says no preview. Opens fine from pc, and if I save on tablet, but that is a pain. Any suggestions appreciated. I do have excel on tablet, opens all csv files as supposed to.