I played this version for a while, there are three crashes in Campaign mode. These screenshots are the exact moments when it crashed.
Two of them happened during a fight, not sure what triggered it, but both have intense amount of arrows firing.
One of the crash happened during the card placement phase. If I remember correctly, it happened after I'm placed a stone wall in between a semi-hexagon of 2nd story battlements, then I proceeded to click the Alchemist block.