I may have found what causes the problem, though I can't help with a fix unless you have a save before unlocking a Judgement.
Mine was with 'Judging Rainier' instead but luckly I had a save just before completing the War Map operation to unlock it so I managed to revert back. I tried again and it still continued to happened.
However I noticed that I had judgements still outstanding before I unlocked Rainier, so I finished those and tried Rainier again and this time it worked. Seems that having multiple judgements can cause problems (I had two outstanding, the Duchess and Mistriss Poulin, the later one was a surprise as I hadn't turned in that quest, it's still in my Journal as incomplete).