I rushed military technology (in a quick start game) to see what happened next, but after clicking on turn button at the 249th turn, my game crashed :/.
I am sure that the game crashed because it's alpha, so i report this problem to fix it 
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My Pc is totally ok, it was not the cause of this crash.
Yesterday i played too, but in normal game, and i got a crash after 140 turns .
If i could help programmers by reporting those problems, i will be happy
If my English is not enough good to understand all, excuse me, i am a French student , and i accept all advice to improve it .