I just finished playing a huge random single-star map with me and 9 hard AI FFA. After about 2 hours of play, I took a screenshot with steam, and attempted to view it while in-game, and it crashed due to a C++ runtime error.
(The next ones are probably unrelated.)
Later, about every 30-45 minutes or so the game would just go black screen and then exit to desktop. No error message was given, and all mini-dump files are 0kb in size and contain no data. A number of them, at least, happened RIGHT AFTER and autosave had occurred, which was convenient, but might also be the cause.
My graphical settings were the defaults, except the resolution is 1920x1080. graphics card is Nvidia GForce GT 330 M (laptop) and I have current drivers. I haven't tried reinstalling it, yet, but I kind of doubt it will help.
I suppose it could be due to it capping out its memory, since it's a 32-bit game and there were lots of ships milling about (I was vasari loyalists with maxed fleet and cap ships).