thanks for the fast replies, i found 2 of the logs youre looking for, but 'UnhandledErrors.txt' wasnt in my ai war folder.
i only have one autosave left. played with a friend via steam a coop round, after the first crash he hosted the game, but it crashed 2 times again.
my fleet was quite large, about 2500 units, my friend had the same, but a little bit smaller afair. anyways, some days ago, i had some similar fleet and the game was fine without any problems. so i wouldnt say they were exceptionally large.
i cant tell you how to replicate the crashes. first time it happened in the galaxy map, the second time while dragging a box around my whole units. the third time was in the game menue afair, but I'm not sure about that.
i try that fileswap thingy, thanks for the help!