Meet Leng Spider in 6-3 Normal. Discard Charming Longsword. Dialogue boxes pop up to ask whether to use Diplomacy or Combat, but the boxes themselves are empty blue rectangles. They do work when pressed.

 

1.2.8.1, iPad Air 2, iOS 10.3.3.

Thanks for the find! I have been able to reproduce and fix this issue.

Issue is still open.

For those who don’t feel like guessing, the top button is for Diplomacy