I was playing a single player level, an ad popped up on the bottom of the screen, and the game reacted as if I had surrendered. Meaning, my armies disappeared and the AI's went on playing each other. Very strange...and very annoying.

This happens? I don't know how ads popping up can force-surrender you. I've not had that happen myself but IDK how to fix it.

Go here about it: https://www.warlight.net/ReportBug