I always play in windowed mode and I don't know if there's a pattern. My recollection is that each time I was just scanning my civ on the main map. It didn't crash yesterday so I guess I'll need to keep observing.
Or, Occam's Razor: My laptop is dying and it's just a coincidence that it crashed during CIV two days in a row. I've had these kind of crashes several times in the past, but things had been running smoothly for the last month or so until the CIV crashes.
Or, Occam's Razor: My laptop is dying and it's just a coincidence that it crashed during CIV two days in a row. I've had these kind of crashes several times in the past, but things had been running smoothly for the last month or so until the CIV crashes.

I hate that it prompts you when you move onto a tile occupied by someone else's unit and you're not at war with them.
As penance you must recite the St. Crispin's Day speech from Shakespeare's