it worked all the time in CC 2015 as well, i recently updated (a day ago) to CC 2017 photoshop. I did it this morning, doing it for the 2nd time today, without changing any photoshop settings and having closed photoshop this morning and re-opening it just a few mins ago, suddenly generate normal map is not working. In CC 2017, cc says there are no current updates for it, generate normal map is not working.
