I had the same problem twice. I play on PC. Both times happened after I judged the person once and then I reloaded immediately to a save right before the judgement to try another option (I'm just curious what would be different...)
The first instance was some time ago so I can't remember the person I judged. It was definitely a minor one from a wartable mission and before both "Wicked Eyes and Wicked Hearts" and "Here Lies the Abyss". That time I restarted the game and I reloaded an earlier save from before getting the mission report, i.e. before that person could be judged, and that worked.
The second time was just now, and it was Lord Erimond right after returning from "Here Lies the Abyss". I tried reloading an earlier save from after returning to skyhold, but that didn't work. I had spent the last hour speaking to all the companions and whatnot so I'd really like to not have to load the save from before killing the Nightmare... After searching the forums, I found this thread and wanted to try the repair game option but it's greyed out in Origin. Finally I restarted my game and tried the same save file again, and that worked for me.
So it seems that a restart fixes the problem, hope this helps.