Although that makes me wonder… On my system it doesn’t open and I have the full Acrobat DC included with Creative Cloud. And the person I have testing it I think is also on at the very least an Acrobat Pro version. Does Lectora limit its functionality to just Adobe Reader, or would either Reader or Acrobat work? Or any PDF viewer for that matter as long as it’s set in the computer’s defaults? Now, our customers themselves, or really customers’ customers, would only have Reader installed so maybe just testing on a more similar system will verify.